Moonfin web client not loading, requesting /Moonfin/Moonfin/Web/loader.js

[steven-edgar]

I've been struggling to get the Moonfin web client to work with Jellyfin. Plugin is installed and shows as active, as does the FileTransformation plugin, but every time I click on the Moonfin icon at the top right of the Jellyfin web client all I get is the Moonfin logo, which never goes away.

Looking at the browser developer tools, I can see it failing to load loader.js, and the reason for that is the path appears to be wrong,

/Moonfin/Moonfin/Web/loader.js

Everything else appears to be loading from the expected paths, without the double "/Moonfin".

I tried redirecting the above path using my Caddy reverse proxy to give it the correct path, and that then removed the error I saw in developer tools, but the Moonfin loader screen still never disappears, and there are no more errors in the developer tools network log after I've done this, so I've no idea why the loader screen appears to be stuck, but I guess it's related to the same root cause.

There is no base URL configured in Jellyfin, but I tried setting it to "/" but it made no difference.

I originally had no forced server URI set in Jellyfin, I've since set this but it made no difference either.

Accessing without going through the reverse proxy gives the exact same symptoms.

I've tried uninstalling both plugins, clearing the cache directory, hard-restarting Jellyfin, re-installing and then restarting again, no change.

Using incognito mode on the browser, no change.

I did notice that if I look in browser developer tools when loading the main Jellyfin web client, not the Moonfin one, it tries successfully to load /Moonfin/Web/loader.js, I'm unsure if this is expected or not, but if FileTransformation is prepending this path with "/Moonfin" when I try to load the Moonfin web client then that would explain the error, but not the root cause.

No errors about Moonfin, Moonbase or FileTransformation in the Jellyfin log.

Using the Moonfin android app or Linux native client appears to work ok with the same server.

Jellyfin v10.11.11

FileTransformer v3.0.2.0

Moonfin v2.4.0.0

OS is Ubuntu server 26.04 with all current updates.