Serviio

I don't think you did anything wrong. I fact - I believe twitch API was changed once again, and now a call that fetches thumbnail fails. I've created an issue that the plugin developer could check hopefully: https://github.com/bogenpirat/serviio-plugins/issues/6 .

For now, as a workaround, you can try commenting out the thumbnail functionality. This way it works for me.
In twitch.groovy just comment out (or delete) lines 207-212 and line 225.

Or just use the file attached where it's done already.

Just tried now, plugin not working for me - anyone still use that? (tried with stock ffmpeg becouse patched one not available). First i got http401 error in logs then timeout errors.

BTW that stream url extraction tool working if that help: https://pwn.sh/tools/getstream.html / https://github.com/streamlink/streamlink