Jellyfin: SSA subtitles produce a playback error

[PoepiePeppie]

Whenever I play a file that has internal MKV subtitles Jellyfin will give me a playback error saying "there was an issue with the client profiling and the server isn't sending a compatible media format"
After troubleshooting a bit in the matrix channel we found out octopus.js is producing an error when trying to look for subtitles.

*steps to reproduce the behavior: *

1. use 10.5.3
2. open up a file with internal subtitles in SSA format
3. It gives the playback error.

Expected behavior
It plays files with SSA subtitling.

Logs
Direct stream log
https://pastebin.com/qm78Rz4i
transcode log
https://pastebin.com/9EZ2BEPM

Screenshots

System:

• OS: Debian
• Virtualization: None
• Played on browser
• Browser: Firefox 74.1
• Jellyfin Version: 10.5.3
• Playback: Direct Play/Transcoding
• Installed Plugins: OpenSubtitles
• Reverse Proxy: Apache
• Base URL: /jellyfin
• Storage: Local

[frankyifei]

same thing, I went back to 10.5.2

[JustAMan]

A workaround is to set base URL to an empty value until it's fixed.

[hawkinspaul]

Having the same issue, how did you roll back to 10.5.2? I understand that you can do that pretty easily on Docker, but I don't have Docker atm. I'm running proxmox with Ubuntu Server installed. Is it possible to roll back without losing metadata / user data?