Moonfin doesn't start when freshly installed with latest File-Transformation Plugin

[enyineer]

Description

I am trying to use the Moonfin plugin alongside its required dependency, the File Transformation plugin. However, Kestrel is failing to start entirely due to a fatal Dependency Injection (DI) error in the File Transformation plugin.

Because the server is crashing on startup, Moonfin is subsequently failing to load its web interface components, resulting in a canceled request for loader.js.

I attempted to temporarily resolve this by downgrading the File Transformation plugin, but Jellyfin's scheduled tasks keep auto-updating it back to the broken version before I can safely boot. I am reporting this here so the Moonfin team is aware that the current version of their required dependency seems to have issues with Jellyfin 10.11.6.

To Reproduce

1. Run Jellyfin 10.11.6.
2. Install Moonfin v1.5.1.0.
3. Install File Transformation v2.5.4.0 (as required).
4. Restart the Jellyfin server.
5. The server will crash on startup, and Kestrel will fail to bind.

Expected behavior

The File Transformation plugin should register its required DI services so Kestrel can start, allowing Moonfin to serve its loader.js without the request being canceled.

Logs

1. The Moonfin Error (Web UI failing to load):

[2026-02-28 22:06:38.986 +01:00] [ERR] Error processing request: "The operation was canceled". URL "GET" "/Moonfin/Web/loader.js".

jellyfin20260228.log

[enyineer]

The issue seems to persist even after downgrading File Transformation to 2.5.3.0 and restarting the app.

[enyineer]

Created an upstream PR to - at least for me - fix the issue of the File Transformation startup. Closing this issue as it's not a Moonfin issue.