Filebrowser does not return errors correctly

[azdfzshffg]

Checklist

• This is a bug report, not a question.
• I have searched on the issue tracker for my bug.
• I am running the latest FileBrowser version or have an issue updating.

Version

File Browser 2.41.0

Description

Hello,

The issue is that Filebrowser does not properly return errors when it is behind a proxy.

For example, I have restricted file uploads to certain extensions: .txt, .pdf, and .csv.
If I try to upload a .rpm file, the request is indeed blocked with a 403 by Filebrowser, as expected.

However, the client is not informed — nothing happens in the browser.
The upload simply does not start, but no error message is displayed to the user.

Here is a screenshot that illustrates the issue (file upload silently fails despite being rejected with a 403).

I've also observed the same behavior in other cases:

• Read-only file system

• Permission denied errors

In all these situations, Filebrowser silently fails without any UI feedback when it is behind a reverse proxy.

What did you expect to happen?

expected Filebrowser to properly return an error to the client when an upload fails — for example, by displaying a message such as “Upload not allowed” or “Permission denied,” so that the user understands why the action failed.

What actually happened?

Filebrowser silently fails without any UI feedback when it is behind a reverse proxy.

Reproduction Steps

Set up Filebrowser behind a reverse proxy (e.g. Apache or Nginx).

Configure Filebrowser to allow only certain file types for upload (e.g. .txt, .pdf, .csv).

Attempt to upload a file with a disallowed extension (e.g. .rpm).

Observe that:

Filebrowser returns a 403 Forbidden (can be seen in network logs).

But the browser shows no error or feedback — the upload silently fails.

Files

No response

[ramiresviana]

Are these errors displayed correctly when you access File Browser directly, without the proxy?

[GldRush98]

No, even with out the proxy, the error is not displayed to the end user. It just spins and never uploads.

[azdfzshffg]

I confirm @GldRush98's comment

I tested with the proxy completely removed and still experience the same issue when accessing Filebrowser directly.

Here is an example screenshot:

I can also reproduce the problem with:

• Permission denied ( error 409 on filebrowser LOG)

• Filesystem set to Read-Only

[GldRush98]

Yup, I've noticed the same thing after I set up a bunch of regex filters to only whitelist certain file extensions.