Error during upload, status code 412

When I try to upload a PDF document it generates this error code and says that the document upload failed. But it only happens with pdf documents

this is in console navigator

If you can get the full 412 response it may have a hint in it. Should be available Network when you’re in your browser console/inspector.

It’s also worth checking your Nextcloud Server main log. At least some of the times this condition comes up should leave clues.

Also, are you (presumably the admin) using any file access control (Flow) or other types of inbound/uploaded file processing options or apps?

For anything more you’ll have to provide further basic details about your environment, such as Nextcloud Server version, installation method, operating platform, and topology (e.g. reverse proxy in use, etc.).