ERROR: Server Communication failed

[Leader-board]

Setup

• MW version: 1.39
• PHP version: 8.1.5
• DB (MySQL etc.): MariaDB
• SBL version: 2.0 (SimpleBatchUpload version)
• Browser version: Latest version of Edge, Windows 11. Also reported by other users in our wiki.

Issue

See below
Steps to reproduce:
Upload anything using any method using Special:BatchUpload.
Expected result:
A file should be uploaded.
Observed result:

The error "ERROR: Server communication failed" is observed, and nothing seems to have been uploaded. Normal MediaWiki file upload works without issues.
Stacktrace:
A generic 500 error message upon debugging in the console

[malberts]

Does this happen only with Edge on Windows 11?

I cannot reproduce this with Firefox and Chrome using:

• MW version: 1.39.5
• PHP version: 8.1.24
• DB: MariaDB
• SBL version: 2.0

Do you see any failing API calls in the browser dev tools?

[malberts]

There is also this old issue with the same error message: #25

Did you do any additional LocalSettings config for $wgSimpleBatchUploadMaxFilesPerBatch?

[Leader-board]

Hi Morne, I haven't tested with other browsers, but don't think that's the issue. Here's what the console logs say:

We haven't configured $wgSimpleBatchUploadMaxFilesPerBatch.