Can't compile example withWebSocket: 'DynamicJsonDocument' was not declared in this scope

[selefotsifem]

When I try to compile the example withWebSocket under Arduino 1.8.19 the compilation fails with the error: 'DynamicJsonDocument' was not declared in this scope

I went back to the version 6 of ArduinoJson, because in version 7 the static and dynamic Json document got merged into a single Json document, but with different syntax and the library increased the needed memory footprint. So the usage of DynamicJsonDocument tells me, that I need to use an version 6 (or maybe even older ?) library version.
I tried it with 6.9.0 (the first non beta version 6 and with 6.21.5 (the last version 6), but the error is the same.

Can someone give me an hint, what to do or which version I should use, to get the example compiled.

The first error occurs in

In file included from C:\arduino-1.8.19\portable\sketchbook\libraries\async-esp-fs-webserver\src/AsyncFsWebServer.h:46,
                 from C:\arduino-1.8.19\portable\sketchbook\libraries\async-esp-fs-webserver\examples\withWebSocket\withWebSocket.ino:8:
C:\arduino-1.8.19\portable\sketchbook\libraries\async-esp-fs-webserver\src/SetupConfig.hpp:18:9: error: 'DynamicJsonDocument' does not name a type
   18 |         DynamicJsonDocument* m_doc = nullptr;

Thanks for any usable hint

[selefotsifem]

OK, digged deeper into this issue. I installed a clean Version of Arduino 1.8.19 into a independent directory, created an empty portable subdirectory inside, configured aditional Board source: https://arduino.esp8266.com/stable/package_esp8266com_index.json and installed the esp8266 toolchain.
Than I installed AsyncEspFsWebserver with all dependencies, which installed ArduinoJson 7.4.2

When I compile with this setting the withWebSocket example, I receive errors because of non existing DynamicJsonDocument in

async-esp-fs-webserver/examples/withWebSocket/withWebSocket.ino

Line 131 in 405a95d

DynamicJsonDocument doc(file.size() * 1.33);

and

async-esp-fs-webserver/examples/withWebSocket/withWebSocket.ino

Line 144 in 405a95d

DynamicJsonDocument doc(file.size() * 1.33);

This looks like code written for ArduinoJSON v6, as DynamicJsonDocument was introduced with version 6 and removed in version 7.
I found, that this change was covered in different ways in different locations.
E.g. in SetupConfig.hpp each declaration is made basedd on the ArduinoJSON major version, like:

async-esp-fs-webserver/src/SetupConfig.hpp

Lines 15 to 19 in 405a95d

	#if ARDUINOJSON_VERSION_MAJOR > 6
	JsonDocument* m_doc = nullptr;
	#else
	DynamicJsonDocument* m_doc = nullptr;
	#endif

But in other parts the code seems to be older.

OK, So i tried now different subversions of version 6:
ArduinoJson@6.10.0 and ArduinoJson@6.15.2 give me both a warning about a redefinition of ARDUINOJSON_USE_LONG_LONG and failed finally with this error:
error: 'bool CaptiveRequestHandler::canHandle(AsyncWebServerRequest*) const' marked 'override', but does not override

ArduinoJson@6.21.5 failed only with the override error, the redefinition is gone.

The two lines, which are reported as error are:

async-esp-fs-webserver/src/CaptivePortal.hpp

Lines 34 to 39 in 405a95d

	bool canHandle(AsyncWebServerRequest *request) const override {
	if (request->host() != WiFi.softAPIP().toString())
	return true;
	else
	return false;
	}

and

async-esp-fs-webserver/src/CaptivePortal.hpp

Lines 41 to 46 in 405a95d

	void handleRequest(AsyncWebServerRequest *request) override
	{
	request->redirect(targetURL);
	log_info("Captive handler triggered. Requested %s%s -> redirecting to %s", request->host().c_str(), request->url().c_str(), targetURL.c_str());
	}
	};

I followed the advice found in several locations about similar problems just to delete the ### override statement, but that leads to those errors:

C:\arduino-1.8.19-windows\portable\sketchbook\libraries\AsyncEspFsWebserver\src\AsyncFsWebServer.cpp: In member function 'void AsyncFsWebServer::handleSetup(AsyncWebServerRequest*)':
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\AsyncEspFsWebserver\src\AsyncFsWebServer.cpp:178:133: error: no matching function for call to 'AsyncWebServerRequest::beginResponse(int, const char [10], uint8_t*, unsigned int)'
  178 |     AsyncWebServerResponse *response = request->beginResponse(200, "text/html", (uint8_t*)_acsetup_min_htm, sizeof(_acsetup_min_htm));
      |                                                                                                                                     ^
In file included from C:\arduino-1.8.19-windows\portable\sketchbook\libraries\AsyncEspFsWebserver\src\AsyncFsWebServer.h:7,
                 from C:\arduino-1.8.19-windows\portable\sketchbook\libraries\AsyncEspFsWebserver\src\AsyncFsWebServer.cpp:1:
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:246:29: note: candidate: 'AsyncWebServerResponse* AsyncWebServerRequest::beginResponse(int, const String&, const String&)'
  246 |     AsyncWebServerResponse *beginResponse(int code, const String& contentType=String(), const String& content=String());
      |                             ^~~~~~~~~~~~~
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:246:29: note:   candidate expects 3 arguments, 4 provided
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:247:29: note: candidate: 'AsyncWebServerResponse* AsyncWebServerRequest::beginResponse(AsyncWebServerRequest::FS&, const String&, const String&, bool, AwsTemplateProcessor)'
  247 |     AsyncWebServerResponse *beginResponse(FS &fs, const String& path, const String& contentType=String(), bool download=false, AwsTemplateProcessor callback=nullptr);
      |                             ^~~~~~~~~~~~~
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:247:47: note:   no known conversion for argument 1 from 'int' to 'AsyncWebServerRequest::FS&' {aka 'fs::FS&'}
  247 |     AsyncWebServerResponse *beginResponse(FS &fs, const String& path, const String& contentType=String(), bool download=false, AwsTemplateProcessor callback=nullptr);
      |                                           ~~~~^~
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:248:29: note: candidate: 'AsyncWebServerResponse* AsyncWebServerRequest::beginResponse(AsyncWebServerRequest::File, const String&, const String&, bool, AwsTemplateProcessor)'
  248 |     AsyncWebServerResponse *beginResponse(File content, const String& path, const String& contentType=String(), bool download=false, AwsTemplateProcessor callback=nullptr);
      |                             ^~~~~~~~~~~~~
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:248:48: note:   no known conversion for argument 1 from 'int' to 'AsyncWebServerRequest::File' {aka 'fs::File'}
  248 |     AsyncWebServerResponse *beginResponse(File content, const String& path, const String& contentType=String(), bool download=false, AwsTemplateProcessor callback=nullptr);
      |                                           ~~~~~^~~~~~~
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:249:29: note: candidate: 'AsyncWebServerResponse* AsyncWebServerRequest::beginResponse(Stream&, const String&, size_t, AwsTemplateProcessor)'
  249 |     AsyncWebServerResponse *beginResponse(Stream &stream, const String& contentType, size_t len, AwsTemplateProcessor callback=nullptr);
      |                             ^~~~~~~~~~~~~
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:249:51: note:   no known conversion for argument 1 from 'int' to 'Stream&'
  249 |     AsyncWebServerResponse *beginResponse(Stream &stream, const String& contentType, size_t len, AwsTemplateProcessor callback=nullptr);
      |                                           ~~~~~~~~^~~~~~
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:250:29: note: candidate: 'AsyncWebServerResponse* AsyncWebServerRequest::beginResponse(const String&, size_t, AwsResponseFiller, AwsTemplateProcessor)'
  250 |     AsyncWebServerResponse *beginResponse(const String& contentType, size_t len, AwsResponseFiller callback, AwsTemplateProcessor templateCallback=nullptr);
      |                             ^~~~~~~~~~~~~
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:250:100: note:   no known conversion for argument 3 from 'uint8_t*' {aka 'unsigned char*'} to 'AwsResponseFiller' {aka 'std::function<unsigned int(unsigned char*, unsigned int, unsigned int)>'}
  250 |     AsyncWebServerResponse *beginResponse(const String& contentType, size_t len, AwsResponseFiller callback, AwsTemplateProcessor templateCallback=nullptr);
      |                                                                                  ~~~~~~~~~~~~~~~~~~^~~~~~~~
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\AsyncEspFsWebserver\src\AsyncFsWebServer.cpp: In member function 'void AsyncFsWebServer::handleFileEdit(AsyncWebServerRequest*)':
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\AsyncEspFsWebserver\src\AsyncFsWebServer.cpp:711:131: error: no matching function for call to 'AsyncWebServerRequest::beginResponse(int, const char [10], uint8_t*, unsigned int)'
  711 |     AsyncWebServerResponse *response = request->beginResponse(200, "text/html", (uint8_t*)_acedit_min_htm, sizeof(_acedit_min_htm));
      |                                                                                                                                   ^
In file included from C:\arduino-1.8.19-windows\portable\sketchbook\libraries\AsyncEspFsWebserver\src\AsyncFsWebServer.h:7,
                 from C:\arduino-1.8.19-windows\portable\sketchbook\libraries\AsyncEspFsWebserver\src\AsyncFsWebServer.cpp:1:
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:246:29: note: candidate: 'AsyncWebServerResponse* AsyncWebServerRequest::beginResponse(int, const String&, const String&)'
  246 |     AsyncWebServerResponse *beginResponse(int code, const String& contentType=String(), const String& content=String());
      |                             ^~~~~~~~~~~~~
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:246:29: note:   candidate expects 3 arguments, 4 provided
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:247:29: note: candidate: 'AsyncWebServerResponse* AsyncWebServerRequest::beginResponse(AsyncWebServerRequest::FS&, const String&, const String&, bool, AwsTemplateProcessor)'
  247 |     AsyncWebServerResponse *beginResponse(FS &fs, const String& path, const String& contentType=String(), bool download=false, AwsTemplateProcessor callback=nullptr);
      |                             ^~~~~~~~~~~~~
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:247:47: note:   no known conversion for argument 1 from 'int' to 'AsyncWebServerRequest::FS&' {aka 'fs::FS&'}
  247 |     AsyncWebServerResponse *beginResponse(FS &fs, const String& path, const String& contentType=String(), bool download=false, AwsTemplateProcessor callback=nullptr);
      |                                           ~~~~^~
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:248:29: note: candidate: 'AsyncWebServerResponse* AsyncWebServerRequest::beginResponse(AsyncWebServerRequest::File, const String&, const String&, bool, AwsTemplateProcessor)'
  248 |     AsyncWebServerResponse *beginResponse(File content, const String& path, const String& contentType=String(), bool download=false, AwsTemplateProcessor callback=nullptr);
      |                             ^~~~~~~~~~~~~
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:248:48: note:   no known conversion for argument 1 from 'int' to 'AsyncWebServerRequest::File' {aka 'fs::File'}
  248 |     AsyncWebServerResponse *beginResponse(File content, const String& path, const String& contentType=String(), bool download=false, AwsTemplateProcessor callback=nullptr);
      |                                           ~~~~~^~~~~~~
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:249:29: note: candidate: 'AsyncWebServerResponse* AsyncWebServerRequest::beginResponse(Stream&, const String&, size_t, AwsTemplateProcessor)'
  249 |     AsyncWebServerResponse *beginResponse(Stream &stream, const String& contentType, size_t len, AwsTemplateProcessor callback=nullptr);
      |                             ^~~~~~~~~~~~~
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:249:51: note:   no known conversion for argument 1 from 'int' to 'Stream&'
  249 |     AsyncWebServerResponse *beginResponse(Stream &stream, const String& contentType, size_t len, AwsTemplateProcessor callback=nullptr);
      |                                           ~~~~~~~~^~~~~~
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:250:29: note: candidate: 'AsyncWebServerResponse* AsyncWebServerRequest::beginResponse(const String&, size_t, AwsResponseFiller, AwsTemplateProcessor)'
  250 |     AsyncWebServerResponse *beginResponse(const String& contentType, size_t len, AwsResponseFiller callback, AwsTemplateProcessor templateCallback=nullptr);
      |                             ^~~~~~~~~~~~~
C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:250:100: note:   no known conversion for argument 3 from 'uint8_t*' {aka 'unsigned char*'} to 'AwsResponseFiller' {aka 'std::function<unsigned int(unsigned char*, unsigned int, unsigned int)>'}
  250 |     AsyncWebServerResponse *beginResponse(const String& contentType, size_t len, AwsResponseFiller callback, AwsTemplateProcessor templateCallback=nullptr);
      |                                                                                  ~~~~~~~~~~~~~~~~~~^~~~~~~~

And here I have not really a further idea.
Perhaps I need to go back to older versions of other libraries.

Besides my hope to get helping hints, I found, that it would be helpful when every example would contain the lines of used libraries when compiling the working example. My current output looks like this:

Bibliothek ESP8266mDNS in Version 1.2 im Ordner: C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\libraries\ESP8266mDNS  wird verwendet
Bibliothek ESP8266WiFi in Version 1.0 im Ordner: C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\libraries\ESP8266WiFi  wird verwendet
Bibliothek LittleFS in Version 0.1.0 im Ordner: C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\libraries\LittleFS  wird verwendet
Bibliothek AsyncEspFsWebserver in Version 2.0.2 im Ordner: C:\arduino-1.8.19-windows\portable\sketchbook\libraries\AsyncEspFsWebserver  wird verwendet
Bibliothek DNSServer in Version 1.1.1 im Ordner: C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\libraries\DNSServer  wird verwendet
Bibliothek ESPAsyncWebServer in Version 3.1.0 im Ordner: C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer  wird verwendet
Bibliothek ESPAsyncTCP in Version 1.2.4 im Ordner: C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncTCP  wird verwendet
Bibliothek Hash in Version 1.0 im Ordner: C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\libraries\Hash  wird verwendet
Bibliothek ArduinoJson in Version 6.21.5 im Ordner: C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ArduinoJson  wird verwendet

Those lines in each example, would be very helpful. I am sure, that the examples compiled without errors, at the time of writing.
But it is very hard to figure out, which combination of libraries were used at this time.

[cotestatnt]

Hi @selefotsifem
The library should work with both version 6 and version 7, but the examples are written for version 7, so if you want to use the previous one you’ll need to adapt them accordingly.

At the moment, I’m also working on a new release (dev branch) that completely removes the internal dependency on the ArduinoJson library, allowing you to use any library/version you prefer in your sketch.

[cotestatnt]

Bibliothek ESPAsyncWebServer in Version 3.1.0 im Ordner: C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer wird verwendet
Bibliothek ESPAsyncTCP in Version 1.2.4 im Ordner: C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncTCP wird verwendet

I also noticed that you’re using very old versions of these two libraries and that the path is not the one created by the ‘official’ libraries. You’ve probably installed some no-longer-maintained fork: in fact, until some time ago the ESPAsyncWebServer library couldn’t be installed through the Arduino IDE library manager, and some users created their own forks.
The ‘official’ repository is the one mentioned in the readme (user @ESP32Async).

[selefotsifem]

I also noticed that you’re using very old versions of these two libraries and that the path is not the one created by the ‘official’ libraries. You’ve probably installed some no-longer-maintained fork: in fact, until some time ago the ESPAsyncWebServer library couldn’t be installed through the Arduino IDE library manager, and some users created their own forks. The ‘official’ repository is the one mentioned in the readme (user @ESP32Async).

As I explained in my second post, I use the official libraries, Arduino installs as dependencies when installing AsyncEspFsWebserver .
I use the portable subdirectory, which forces Arduino to install everything into this directory, instead to the official directories in the users home-directory. This method allows having clean environments, unfortunately it is not yet migrated into the Arduino V2.

So all my path structures are official Arduino. This is how the installation looks like:

and after that, I have the most recent versions installed, Arduino offers!

I have just repeated this step after deleting my previous portable-Directory and have the same versions here.

edit:
Another remark: The example I try to compile, does NOT work with ArduinoJson 7.x, as it still uses DynamicJsonDocument, which is not longer available in v7.

[cotestatnt]

Hi @selefotsifem
From what I was able to verify, in order to differentiate the repository from the various “clones,” the names of the ESP32Async libraries were modified by adding spaces betweeen words like "ESP Async WebServer" or "ESP Async TCP"
Unfortunately, I didn’t reflect these updates in my library.properties, so the “full” installation of dependencies ends up pulling the old versions that point to the forks. I didn’t notice this because I usually install them one at a time and never all together.

By the way, this is not the reason for error on compile.
AsyncFsWebServer supports both version 6 and version 7 of ArduinoJson, but so far I’ve only tested it successfully the v6 with ESP32 boards.
With ESP8266 the error occurs. I still need to investigate, but it might depend on ArduinoJson itself: the ESP8266 has less SRAM, and a different allocation strategy may be required.

To be honest, I don’t have much time available for this work, especially for a microcontroller that I haven’t used in years, considering that it can be replaced at practically the same cost and size with an ESP32. Even the development of the ESP8266 Arduino core itself seems to have been abandoned, as it has been stuck at version 3.1.2 for a couple of years now.

[selefotsifem]

Hello @cotestatnt,

By the way, this is not the reason for error on compile. AsyncFsWebServer supports both version 6 and version 7 of ArduinoJson, but so far I’ve only tested it successfully the v6 with ESP32 boards. With ESP8266 the error occurs. I still need to investigate, but it might depend on ArduinoJson itself: the ESP8266 has less SRAM, and a different allocation strategy may be required.

I can't believe, that this is the problem, as I stuck with compile problems. This kind of problem may be the next, once the sketch compiles.

To be honest, I don’t have much time available for this work, especially for a microcontroller that I haven’t used in years, considering that it can be replaced at practically the same cost and size with an ESP32. Even the development of the ESP8266 Arduino core itself seems to have been abandoned, as it has been stuck at version 3.1.2 for a couple of years now.

I understand that, but I still sit on a big bunch of those controllers, and was planning a christmas event for a group of kids. So throwing away existing hardware is no option for me.

I keep you posted on my findings.

BTW: Adding the list of used library-versions in each example documentation would be perfect for future examples. As with this information you have an point from where you can start investigating by upgrading single libraries with this kind of errors.

[cotestatnt]

If you want, stay tuned to the dev branch. As I was saying, I am completely removing the ArduinoJson dependency in favor of cJSON, which will be directly included in the source code.

I'm well along and very satisfied; I just need to fix a few minor things. I also took the opportunity to implement some improvements and reduce the footprint of the library itself, and to renovate the /setup interface with a slightly more modern look.

[selefotsifem]

Ok, I made more progress.
Again I cleaned my portable directory and installed:

• ESPAsyncWebServer
• ESPAsyncTCP
• AsyncTCP
• async-esp-fs-webserver

from github as most recent version
Than I installed

• ArduinoJson 6.21.5

via Arduino Library Manager, as my chosen example "withWebSocket" needs a version 6. It still makes use of
DynamicJsonDocument!

And again I got a bunch of compilation errors besides the claim, that there is no prototype for DynamicJsonDocument. This sounded strange, as I have explicitly installed the newest v6 version defining this type.
Next, I detected, that in the list of used libraries there was no reference to ArduinoJson.
So I went into AsyncFsWebServer.h

async-esp-fs-webserver/src/AsyncFsWebServer.h

Lines 49 to 50 in 6382814

	#define ARDUINOJSON_USE_LONG_LONG 1
	#include <ArduinoJson.h>

and added after line 50 the line
pragma message "ArduinoJSON-included-here-#########"
and when I started the next compile I missed this message.

I remembered strange Arduino behaviour, when not including libraries in the very first lines and I moved lines 49 and 50 up to line 6.

And now the sketch compiles without any further problem and only the pragma message appearing.
I went through the .h file trying to understand why this happens, but the reason seems to be hidden in the cryptic Arduino way working with includes.

I could upload to to an ESP, see the messages on serial port, but the sketch crashes when trying to load the start page.

This is now the next level in debugging I will dive into.

However compilation is working now with this change. Just to let you know.

[selefotsifem]

And one more of the good news: The crash only happens when calling "http://192.168.4.1/". Calling "http://192.168.4.1/edit" and "http://192.168.4.1/setup" works as expected!

[selefotsifem]

OK, I spent some more time in digging into the exception.
From the code, serving / should be an easy thing.

async-esp-fs-webserver/examples/withWebSocket/withWebSocket.ino

Lines 189 to 191 in 488e398

	// Add custom page handlers
	server.on("/", HTTP_GET, [](AsyncWebServerRequest *request){
	request->send(200, "text/html", homepage);

with homepage being defined here:

async-esp-fs-webserver/examples/withWebSocket/index_htm.h

Lines 1 to 106 in 488e398

	static const char homepage[] PROGMEM = R"EOF(
	<!DOCTYPE html>
	<html>
	<head>
	<meta http-equiv="Content-type" content="text/html; charset=utf-8">
	<title>WebSocket test page</title>
	<style type="text/css" media="screen">
	body {width: 70%; margin: auto; background-color: black; color: #55ff55; font-family: monospace; text-align: center; }
	.box {border: 1px solid white; border-radius: 10px; padding: 5px; margin: 10px; }
	.output {color: white; }
	#log {text-align: left; margin: 20px; max-height: 500px; overflow: auto; }
	#input_div, #input_el {line-height: 13px; color: #AAA;}
	#input_el { width:97%; background-color: rgba(0,0,0,0); border: 0px;}
	#input_el:focus {outline: none; }
	#icon-setup{float: left;margin: 20px}
	</style>
	<script type="text/javascript">
	var ws = null;
	function ge(s){ return document.getElementById(s);} // Shorthand for get element
	function ce(s){ return document.createElement(s);} // Shorthand for create element
	function stb(){ window.scrollTo(0, document.body.scrollHeight || document.documentElement.scrollHeight); } // Scroll to bottom
	// This function will add a message to the HTML element with id 'log'
	function addMessage(m){
	var msg = ce("div");
	msg.innerText = m;
	ge("log").appendChild(msg);
	stb();
	}
	// If msg is a obj data tyep, handle it (just timestamp in this example) otherwise add to log console
	function parseMessage(msg) {
	try {
	const obj = JSON.parse(msg);
	if (typeof obj === 'object' && obj !== null) {
	if (obj.esptime !== null) {
	var date = new Date(0); // The 0 sets the date to epoch
	if( date.setUTCSeconds(obj.esptime))
	document.getElementById("esp-time").innerHTML = date;
	}
	}
	} catch {
	addMessage(msg);
	}
	}
	// Configure and start WebSocket client
	function startSocket(){
	ws = new WebSocket('ws://'+document.location.host+'/ws',['arduino']);
	ws.binaryType = "arraybuffer";
	ws.onopen = function(e){
	addMessage("WebSocket client connected to " + 'ws://'+document.location.host+'/ws');
	};
	ws.onclose = function(e){
	addMessage("WebSocket client disconnected");
	};
	ws.onerror = function(e){
	console.log("ws error", e);
	addMessage("Error");
	};
	ws.onmessage = function(e){
	parseMessage(e.data)
	};
	// Add event "keydown" listener to input box
	ge("input_el").onkeydown = function(e){
	stb();
	if(e.keyCode == 13 && ge("input_el").value != ""){
	ws.send(ge("input_el").value);
	ge("input_el").value = "";
	}
	}
	}
	// When page is fully loaded start connection
	function onBodyLoad(){
	startSocket();
	}
	</script>
	</head>
	<body id="body" onload="onBodyLoad()">
	<div class=icon>
	<a id=icon-setup href=/setup>
	<svg width="48" height="48" fill=#55ff55 viewBox="0 0 24 24">
	<path d="M12,8A4,4 0 0,1 16,12A4,4 0 0,1 12,16A4,4 0 0,1 8,12A4,4 0 0,1 12,8M12,10A2,2 0 0,0 10,12A2,2 0 0,0 12,14A2,2 0 0,0 14,12A2,2 0 0,0 12,10M10,22C9.75,22 9.54,21.82 9.5,21.58L9.13,18.93C8.5,18.68 7.96,18.34 7.44,17.94L4.95,18.95C4.73,19.03 4.46,18.95 4.34,18.73L2.34,15.27C2.21,15.05 2.27,14.78 2.46,14.63L4.57,12.97L4.5,12L4.57,11L2.46,9.37C2.27,9.22 2.21,8.95 2.34,8.73L4.34,5.27C4.46,5.05 4.73,4.96 4.95,5.05L7.44,6.05C7.96,5.66 8.5,5.32 9.13,5.07L9.5,2.42C9.54,2.18 9.75,2 10,2H14C14.25,2 14.46,2.18 14.5,2.42L14.87,5.07C15.5,5.32 16.04,5.66 16.56,6.05L19.05,5.05C19.27,4.96 19.54,5.05 19.66,5.27L21.66,8.73C21.79,8.95 21.73,9.22 21.54,9.37L19.43,11L19.5,12L19.43,13L21.54,14.63C21.73,14.78 21.79,15.05 21.66,15.27L19.66,18.73C19.54,18.95 19.27,19.04 19.05,18.95L16.56,17.95C16.04,18.34 15.5,18.68 14.87,18.93L14.5,21.58C14.46,21.82 14.25,22 14,22H10M11.25,4L10.88,6.61C9.68,6.86 8.62,7.5 7.85,8.39L5.44,7.35L4.69,8.65L6.8,10.2C6.4,11.37 6.4,12.64 6.8,13.8L4.68,15.36L5.43,16.66L7.86,15.62C8.63,16.5 9.68,17.14 10.87,17.38L11.24,20H12.76L13.13,17.39C14.32,17.14 15.37,16.5 16.14,15.62L18.57,16.66L19.32,15.36L17.2,13.81C17.6,12.64 17.6,11.37 17.2,10.2L19.31,8.65L18.56,7.35L16.15,8.39C15.38,7.5 14.32,6.86 13.12,6.62L12.75,4H11.25Z" />
	</svg>
	</a>
	</div>
	<div class="box">
	<p>ESP current time, sync with NTP server and sent to this client via <a href="https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API/">WebSocket!</a></p>
	<h4 id='esp-time'>Waiting websocket connection...</h4>
	</div>
	<div class="box">
	$<input type="text" value="" id="input_el">
	</div>
	<div class=box>
	<main id=log></main>
	</div>
	</body>
	</html>
	)EOF";

The decoded stack trace looks like this:

Exception 3: LoadStoreError: Processor internal physical address or data error during load or store
PC: 0x4000bf64
EXCVADDR: 0x4025ac8d

Decoding stack results
0x40217cc8: AsyncBasicResponse::AsyncBasicResponse(int, char const*, char const*) at C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src\WebResponses.cpp line 262
0x40215fb8: AsyncWebServerRequest::beginResponse(int, char const*, char const*, std::function ) at C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src\WebRequest.cpp line 880
0x40100de4: malloc(size_t) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\umm_malloc\umm_malloc.cpp line 912
0x40215fc4: AsyncWebServerRequest::beginResponse(int, char const*, char const*, std::function ) at C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src\WebRequest.cpp line 880
0x40100a62: umm_free_core(umm_heap_context_t*, void*) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\umm_malloc\umm_malloc.cpp line 642
0x4020588f: std::_Function_handler   >::_M_invoke(const std::_Any_data &, AsyncWebServerRequest *&&) at c:\arduino-1.8.19-windows\portable\packages\esp8266\tools\xtensa-lx106-elf-gcc\3.1.0-gcc10.3-e5f9fec\xtensa-lx106-elf\include\c++\10.3.0\bits/std_function.h line 498
0x4021cce0: String::equals(String const&) const at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\WString.cpp line 542
0x40214a1d: AsyncCallbackWebHandler::handleRequest(AsyncWebServerRequest*) at c:\arduino-1.8.19-windows\portable\packages\esp8266\tools\xtensa-lx106-elf-gcc\3.1.0-gcc10.3-e5f9fec\xtensa-lx106-elf\include\c++\10.3.0\bits/std_function.h line 617
0x402154d6: AsyncWebServerRequest::_parseReqHeader() at c:\arduino-1.8.19-windows\portable\packages\esp8266\tools\xtensa-lx106-elf-gcc\3.1.0-gcc10.3-e5f9fec\xtensa-lx106-elf\include\c++\10.3.0\ext/new_allocator.h line 103
0x40100de4: malloc(size_t) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\umm_malloc\umm_malloc.cpp line 912
0x40215070: std::_Function_handler   >::_M_invoke(const std::_Any_data &) at c:\arduino-1.8.19-windows\portable\packages\esp8266\tools\xtensa-lx106-elf-gcc\3.1.0-gcc10.3-e5f9fec\xtensa-lx106-elf\include\c++\10.3.0\bits/std_function.h line 303
0x4022172c: std::_Function_handler  ::  >::_M_manager(std::_Any_data &, const std::_Any_data &, std::_Manager_operation) at c:\arduino-1.8.19-windows\portable\packages\esp8266\tools\xtensa-lx106-elf-gcc\3.1.0-gcc10.3-e5f9fec\xtensa-lx106-elf\include\c++\10.3.0\bits/std_function.h line 268
0x40221720: std::_Function_handler  ::  >::_M_invoke(const std::_Any_data &) at c:\arduino-1.8.19-windows\portable\packages\esp8266\tools\xtensa-lx106-elf-gcc\3.1.0-gcc10.3-e5f9fec\xtensa-lx106-elf\include\c++\10.3.0\bits/invoke.h line 103
0x4021557b: AsyncWebServerRequest::_runMiddlewareChain() at c:\arduino-1.8.19-windows\portable\packages\esp8266\tools\xtensa-lx106-elf-gcc\3.1.0-gcc10.3-e5f9fec\xtensa-lx106-elf\include\c++\10.3.0\bits/std_function.h line 303
0x40221740: std::_Function_handler   >::_M_manager(std::_Any_data &, const std::_Any_data &, std::_Manager_operation) at c:\arduino-1.8.19-windows\portable\packages\esp8266\tools\xtensa-lx106-elf-gcc\3.1.0-gcc10.3-e5f9fec\xtensa-lx106-elf\include\c++\10.3.0\bits/std_function.h line 268
0x40215050: std::_Function_handler   >::_M_invoke(const std::_Any_data &) at c:\arduino-1.8.19-windows\portable\packages\esp8266\tools\xtensa-lx106-elf-gcc\3.1.0-gcc10.3-e5f9fec\xtensa-lx106-elf\include\c++\10.3.0\bits/invoke.h line 103
0x402163f8: AsyncWebServerRequest::_parseLine() at C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src\WebRequest.cpp line 688
0x40216fcc: AsyncWebServerRequest::_onData(void*, unsigned int) at C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncWebServer\src\WebRequest.cpp line 159
0x40100db0: free(void*) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\umm_malloc\umm_malloc.cpp line 688
0x40219b5c: AsyncClient::_recv(std::shared_ptr &, tcp_pcb*, pbuf*, int) at C:\arduino-1.8.19-windows\portable\sketchbook\libraries\ESPAsyncTCP\src/ESPAsyncTCP.h line 103
0x40100a62: umm_free_core(umm_heap_context_t*, void*) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\umm_malloc\umm_malloc.cpp line 642
0x40219bbc: AsyncClient::_s_recv(void*, tcp_pcb*, pbuf*, int) at c:\arduino-1.8.19-windows\portable\packages\esp8266\tools\xtensa-lx106-elf-gcc\3.1.0-gcc10.3-e5f9fec\xtensa-lx106-elf\include\c++\10.3.0\bits/shared_ptr_base.h line 1324
0x40230759: tcp_input at core/tcp_in.c line 501
0x4022d37c: mem_free at core/mem.c line 236
0x4022d892: pbuf_free_LWIP2 at core/pbuf.c line 786
0x402357f1: ip4_input at core/ipv4/ip4.c line 1467
0x4022d355: mem_malloc at core/mem.c line 210
0x40100a62: umm_free_core(umm_heap_context_t*, void*) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\umm_malloc\umm_malloc.cpp line 642
0x4022ca19: ethernet_input_LWIP2 at netif/ethernet.c line 188
0x4022c82c: esp2glue_ethernet_input at glue-lwip/lwip-git.c line 118
0x402554c5: ethernet_input at glue-esp/lwip-esp.c line 365
0x402554d7: ethernet_input at glue-esp/lwip-esp.c line 373
0x401000ab: app_entry_redefinable() at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\core_esp8266_main.cpp line 386
0x40100438: ets_post(uint8, ETSSignal, ETSParam) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\core_esp8266_main.cpp line 238
0x4021a448: EspClass::flashRead(unsigned int, unsigned int*, unsigned int) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\Esp.cpp line 932
0x4021a448: EspClass::flashRead(unsigned int, unsigned int*, unsigned int) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\Esp.cpp line 932
0x4021a4d5: EspClass::flashRead(unsigned int, unsigned char*, unsigned int) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\Esp.cpp line 911
0x4021a4d5: EspClass::flashRead(unsigned int, unsigned char*, unsigned int) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\Esp.cpp line 911
0x4021a4d5: EspClass::flashRead(unsigned int, unsigned char*, unsigned int) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\Esp.cpp line 911
0x4021a448: EspClass::flashRead(unsigned int, unsigned int*, unsigned int) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\Esp.cpp line 932
0x4021a4d5: EspClass::flashRead(unsigned int, unsigned char*, unsigned int) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\Esp.cpp line 911
0x4020b454: esp8266::MDNSImplementation::MDNSResponder::stcMDNSSendParameter::addDomainCacheItem(void const*, bool, unsigned short) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\libraries\ESP8266mDNS\src\LEAmDNS_Structs.cpp line 2173
0x40100de4: malloc(size_t) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\umm_malloc\umm_malloc.cpp line 912
0x4021d5a7: operator new(unsigned int) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\abi.cpp line 41
0x4020c049: esp8266::MDNSImplementation::MDNSResponder::_udpAppendBuffer(unsigned char const*, unsigned int) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\libraries\ESP8266mDNS\src\LEAmDNS_Transfer.cpp line 1163
0x4020c34e: esp8266::MDNSImplementation::MDNSResponder::_writeMDNSRRDomain(esp8266::MDNSImplementation::MDNSResponder::stcMDNS_RRDomain const&, esp8266::MDNSImplementation::MDNSResponder::stcMDNSSendParameter&) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\libraries\ESP8266mDNS\src\LEAmDNS_Transfer.cpp line 1395
0x4020c508: esp8266::MDNSImplementation::MDNSResponder::_writeMDNSServiceDomain(esp8266::MDNSImplementation::MDNSResponder::stcMDNSService const&, bool, bool, esp8266::MDNSImplementation::MDNSResponder::stcMDNSSendParameter&) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\libraries\ESP8266mDNS\src\LEAmDNS_Transfer.cpp line 1502
0x4020c049: esp8266::MDNSImplementation::MDNSResponder::_udpAppendBuffer(unsigned char const*, unsigned int) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\libraries\ESP8266mDNS\src\LEAmDNS_Transfer.cpp line 1163
0x4020c076: esp8266::MDNSImplementation::MDNSResponder::_udpAppend8(unsigned char) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\libraries\ESP8266mDNS\src\LEAmDNS_Transfer.cpp line 1177
0x4020c18e: esp8266::MDNSImplementation::MDNSResponder::_write8(unsigned char, esp8266::MDNSImplementation::MDNSResponder::stcMDNSSendParameter&) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\libraries\ESP8266mDNS\src\LEAmDNS_Transfer.cpp line 1311
0x4020c4bd: esp8266::MDNSImplementation::MDNSResponder::_writeMDNSServiceDomain(esp8266::MDNSImplementation::MDNSResponder::stcMDNSService const&, bool, bool, esp8266::MDNSImplementation::MDNSResponder::stcMDNSSendParameter&) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\libraries\ESP8266mDNS\src\LEAmDNS_Transfer.cpp line 1477
0x40100438: ets_post(uint8, ETSSignal, ETSParam) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\core_esp8266_main.cpp line 238
0x40229b8c: _svfprintf_r at /workdir/repo/newlib/newlib/libc/stdio/nano-vfprintf.c line 609
0x40229830: __ssputs_r at /workdir/repo/newlib/newlib/libc/stdio/nano-vfprintf.c line 232
0x4022451d: _printf_i at /workdir/repo/newlib/newlib/libc/stdio/nano-vfprintf_i.c line 194
0x40229830: __ssputs_r at /workdir/repo/newlib/newlib/libc/stdio/nano-vfprintf.c line 232
0x4022976c: __ssputs_r at /workdir/repo/newlib/newlib/libc/stdio/nano-vfprintf.c line 182
0x4022464c: _printf_i at /workdir/repo/newlib/newlib/libc/stdio/nano-vfprintf_i.c line 246
0x40100438: ets_post(uint8, ETSSignal, ETSParam) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\core_esp8266_main.cpp line 238
0x40100438: ets_post(uint8, ETSSignal, ETSParam) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\core_esp8266_main.cpp line 238
0x40100438: ets_post(uint8, ETSSignal, ETSParam) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\core_esp8266_main.cpp line 238
0x40100584: millis() at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\core_esp8266_wiring.cpp line 176
0x40209e99: esp8266::MDNSImplementation::MDNSResponder::_updateProbeStatus() at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266/PolledTimeout.h line 185
0x40209da2: esp8266::MDNSImplementation::MDNSResponder::_updateProbeStatus() at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266/PolledTimeout.h line 159
0x40100424: ets_post(uint8, ETSSignal, ETSParam) at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\core_esp8266_main.cpp line 236
0x402099a8: esp8266::polledTimeout::timeoutTemplate   >::expiredOneShot() const at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266/PolledTimeout.h line 235
0x40209ea4: esp8266::MDNSImplementation::MDNSResponder::_updateProbeStatus() at C:\arduino-1.8.19-windows\portable\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266/PolledTimeout.h line 159
0x40220d58: std::_Function_handler ::_M_invoke(std::_Any_data const&, AsyncWebSocket*&&, AsyncWebSocketClient*&&, AwsEventType&&, void*&&, unsigned char*&&, unsigned int&&) at c:\arduino-1.8.19-windows\portable\packages\esp8266\tools\xtensa-lx106-elf-gcc\3.1.0-gcc10.3-e5f9fec\xtensa-lx106-elf\include\c++\10.3.0\bits/std_function.h line 289

Any idea what could happen here?

[selefotsifem]

Ok further research found, that the code in the example needs to be changed:

async-esp-fs-webserver/examples/withWebSocket/withWebSocket.ino

Line 191 in 488e398

request->send(200, "text/html", homepage);

instead send() send_P() must be used.
Changing this line makes the example working.
See here: https://github.com/me-no-dev/ESPAsyncWebServer/blob/master/README.ESP32Async.md#send-large-webpage-from-progmem