For reasons that i don't know about a week ago the site's uploading system bugged out and now everytime i try to upload anything it always gives me the same error, At first i thought it was a temporary issue that was gonna be fixed soon but seeing that an entire week has passed now i honestly believe it is something that's only affecting me but if anyone has had or is having the same problem please i'd like you to tell me how to fix it.

Are you uploading by url from twitter by any chance?

What is your upload workflow?

I managed to trigger this message by using drag and drop and
then rename the file on the local filesystem before completing the upload
I assume moving the file with the same name to a different directory/folder will cause the same result
then fill out all forms / select relevant tag boxes
and press the upload button

this makes a green message box flicker replaced by a red "Error: Unknown error! undefined" message box

I assume in my case the browser can't read the file anymore but starts the upload request anyway. (firefox 135.0 on windows here)

From a non-technical user perspective the preview image on the top of the page makes it look like it will be uploaded just fine.

Looking at the developer console, It is one of those cases where firefox doesn't display a response status code under network (and no error stack message under console)

the request tab shows "no payload for this request"
the response tab shows a generic "400 Bad Request - cloudflare" html response template (can't get the headers to display)

I can imagine a situation where a user;
adds the image from a "to upload" directory,
fills out the fields,
moves said file to a "done" directory
and then pressed the upload button.

Filepicker has likely the same issue.