Vale extension not working on .adoc files

[eescapa-tm]

Type: Bug

Expectation: the Vale extension runs on my .adoc files, showing squiggly lines and highlighting suggestions for improvement and style guide adherence. This is working fine for my colleagues with the same VS Code setup and environment

Reality: I get no suggestions from the extension, although the command line vale . works perfectly

Attempted troulbeshooting: I've tried disabling/re-enabling, reloading the window, and disabling all other extensions. This is all I see in the Output: "SyntaxError: Unexpected end of JSON input" but I'm not sure what JSON it's referring to.

Thanks in advance!

Extension version: 0.30.0
VS Code version: Code 1.103.2 (Universal) (6f17636121051a53c88d3e605c491d22af2ba755, 2025-08-20T16:45:34.255Z)
OS version: Darwin arm64 24.6.0
Modes:
Remote OS version: Linux x64 5.15.0-153-generic

A/B Experiments

vsliv368cf:30146710
binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
996jf627:31283433
pythonrdcb7:31342333
usemplatestapi:31297334
aj953862:31281341
nesew2to5:31336538
agentclaude:31350858
nes-set-on:31351930
testaa123cf:31335227
onetestforazureexpcf:31335614
6abeh943:31336334
envsdeactivate2:31353495
0927b901:31350571
ovs_t:31383295
aa_t:31379598
0cj2b977:31352657
gendocstringf:31379556
asdad:31365766
cloudbuttont:31379625
retryenabled:31370050
todos-1:31384886
3efgi100_wstrepl:31382709
trigger-command-fix:31379601

[dosubot]

Hi @eescapa-tm! I'm Dosu and I’m helping the vale-vscode team.

The Vale VSCode extension only processes files that match its supported languages list, which is determined by internal configuration and utility functions. If .adoc (AsciiDoc) files aren't properly listed or detected, the extension won't analyze them or show suggestions—even if the CLI works fine. The error "SyntaxError: Unexpected end of JSON input" means the extension tried to parse output from Vale but got empty or malformed data, often due to file type misconfiguration or issues passing .adoc files to the CLI.

On Linux systems, version 0.30.0 can also download the wrong binary (MacOS ARM64 instead of Linux), causing the extension to malfunction. You can check this by running file vale-ls in the extension folder; if it shows "Mach-O 64-bit arm64 executable," delete the binary and reload VS Code to force a correct download. The binary should be "ELF 64-bit LSB executable" for Linux source.

If the extension still doesn't work, consider downgrading to version 0.20.0, as this has resolved similar language server startup failures for other users source.

Finally, double-check your .vale.ini and VS Code settings to ensure .adoc files are included and configured for Vale analysis. If your colleagues have it working, compare their extension settings and config files for differences.

To reply, just mention @dosu.

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[eescapa-tm]

Thank you, Dosu! I've tried all the following but to no avail (excuse the pun) :

✅ Tried running file vale-ls in the extensions folder, but both me and my colleague get vale-ls: cannot open 'vale-ls' (No such file or directory). Would that imply the wrong binary was not downloaded?
✅ We're already on v0.20.0
✅ vale.ini does indeed include .adoc files: [*.{md,go,adoc}]
✅ I have mirrored my configuration with my colleague's

I just checked the Output again and now seeing a whole new error log, looking to be repeated failed attempts to connect to the extension server. Are you able to check on your end?

2025-09-15 Vale error log.txt

[dosubot]

The error vale-ls: cannot open 'vale-ls' (No such file or directory) means the language server binary is missing, which will cause the extension to repeatedly fail to connect to the server and log connection errors. This can happen if the extension failed to download or extract the binary, or if there was a race condition during activation. On Linux, this is a known issue—sometimes the wrong binary is downloaded, or none at all, especially in remote setups or with certain extension versions. Restarting VS Code can sometimes trigger a successful download if it's a race condition, but if the binary is still missing, the extension cannot function and will keep logging connection failures in the Output panel source.

If you're on v0.20.0, it should not require the language server, but if you upgraded/downgraded or have a mixed environment (e.g., remote Linux, local Mac), there could be leftover state or partial installs. Try fully uninstalling the extension (including on the remote host), reinstalling, and restarting VS Code. If the problem persists, manually downloading the correct vale-ls binary from the official release page and placing it in the extension folder may resolve it. Make sure the binary is executable and matches your architecture (should be ELF for Linux, not Mach-O) source.

If you continue to see repeated connection failures, it's almost always due to the missing or incompatible vale-ls binary, or a GLIBC version mismatch on Linux source.

To reply, just mention @dosu.

---

^{How did I do? Good | Irrelevant | Incorrect | Verbose | Hallucination | Report 🐛 | Other}    

[eescapa-tm]

I manually downloaded the vale-ls binary as suggested (x86_64 for Linux) and tried placing it in both the ~/.vscode-server/extensions and ~/.vscode-server/extensions/chrischinchilla.vale-vscode-0.20.0 folders (separately, not two separate copies in both folders at once).

file vale-ls now returns:
vale-ls: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=1db27f7aa5b43191f0afb93205acbff3b385dab7, for GNU/Linux 3.2.0, not stripped

but I'm back to getting SyntaxError: Unexpected end of JSON input and no squiggly lines or anything on my .adoc files 🥲 any other suggestions bot, or should we loop in your human?

[dosubot]

The extension is receiving empty or malformed output from the vale-ls process, which causes the SyntaxError: Unexpected end of JSON input error. This usually means vale-ls is crashing or failing to start, often due to runtime issues like missing dependencies (GLIBC version mismatches are common on Linux), permission problems, or a misconfigured .vale.ini file. The extension itself doesn't filter file types or parse JSON—it just launches vale-ls and expects valid responses for all files, including .adoc, so the root cause is almost always in the language server or its environment, not the extension code itself (source).

Try running the vale-ls binary directly from your remote terminal to check for errors or missing libraries. Also, double-check that your .vale.ini is accessible and correctly formatted, and compare your environment variables and permissions with your colleague's working setup. If the CLI works but the extension doesn't, it's likely a runtime or config issue with vale-ls, not the extension (source).

To reply, just mention @dosu.

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^{How did I do? Good | Irrelevant | Incorrect | Verbose | Hallucination | Report 🐛 | Other}    

[eescapa-tm]

I've just tried running the vale-ls vinary directly, and it spent more than several minutes seemingly doing nothing before finally returning:

Content-Length: 75 {"jsonrpc":"2.0","error":{"code":-32700,"message":"Parse error"},"id":null}

Again, vale.ini is definitely accessible and correctly formatted because none of my coworkers are experiencing this issue, and we all have the same environment variables and permissions. Any other ideas to fix this?

[ChrisChinchilla]

@eescapa-tm Dosu is a bot, it may get you into rabbit holes, I will look this during this week.

[eescapa-tm]

hi Chris, just wanted to see if you've had the chance to look into this? Let me know if you'd like me to try anything or send logs/more info. Thanks in advance!

[ChrisChinchilla]

@eescapa-tm Not yet, sorry, this is a side project to my work, and the past few months have been exceptionally busy. I will take a quick look now to see if it's a config-related issue, but if it needs coding, I will need longer.

Contributions in terms of code and sponsorship are always welcome to help!

[ChrisChinchilla]

@eescapa-tm

Already I see something I am a little unclear on…

OS version: Darwin arm64 24.6.0
Modes:
Remote OS version: Linux x64 5.15.0-153-generic

What does this mean? As I also see from the Dosu conversations that you manually downloaded the Linux language server binary. So are you running on macOS or Linux? And your colleagues?

[eescapa-tm]

No worries, I appreciate you looking into this!

My colleagues and I run VS Code on MacBooks (macOS), and we connect to a Linux machine via SSH to work on a Git repository that contains the .vale.ini file

[ChrisChinchilla]

@eescapa-tm

OK, bunch of things after digging in as I think I have it working, but as your setup is a little non-standard, it's hard to be sure…

• Is Vale installed on the remote machine?
• Is the Vale extension installed in the remote instance of VSCode on the remote machine?
• Do you have asciidoc and/or asciidoctor support on the remote machine?