Poor error message for 503 (blocked by IP filtering)

[lf-]

This issue respects the following points:

• This issue is not already reported on GitHub (I've searched it).
• I agree to follow Jellyfin's Code of Conduct.
• This report addresses only a single issue; If you encounter multiple issues, kindly create separate reports for each one.

Describe the bug

This is the error that happens if you mess up the remote IP filters on the Jellyfin instance such that it returns 503 to the /System/Info/Public endpoint: jellyfin/jellyfin#12595

Code:

jellyfin-web/src/lib/jellyfin-apiclient/connectionManager.js

Lines 444 to 449 in b468f0d

	ajax({
	url: `${url}/System/Info/Public`,
	timeout: DEFAULT_CONNECTION_TIMEOUT,
	type: 'GET',
	dataType: 'json'
	}).then(

Notably, this error message does not suggest server misconfiguration, it suggests complete server unreachability: a networking problem. However, it is really easy to do the server misconfiguration, and it should not produce an error suggesting a networking mistake.

I have also written a bug for the server, which also does not log anything if this happens: jellyfin/jellyfin#14008. Regardless of it being easier to debug with server access, the client should produce a better error as well.

Reproduction Steps

1. Allow remote access on Jellyfin and set the allowed remote IP ranges to 1.2.3.4 such that it will fail to connect.
2. Restart jellyfin
3. Try to connect

Expected/Actual behaviour

The error message should say that you are likely blocked by an IP filter on the remote end if the server responds with 503.

Logs

No response

Server version

10.10.7

Web version

10.10.7

Build version

10.10.7

Platform

Linux

Browser

Firefox 136

Additional information

No response