SOLVED: Playback failed because the media is not supported by the client. (LG C1)

[Berek]

Hello everyone, I'm here with a problem I discovered today. When I tried to stream a movie to my LG C1 TV, I received this error message: 'Playback failed because the media is not supported by the client.'
Regardless of the file I tried to stream, I always received the same message.

Strangely, if I try to stream on another TV I have (LG C4), the streaming is always successful.

My current Jellyfin server is running in a container hosted on a Synology NAS. The server is running v. 10.11.4 of Jellyfin, and on the TV, I have the latest version of the native app.

I suspect this has started because of an update, either of the DSM or the container, because everything was working fine before, but lately, there were a few updates, both of the NAS and the Jellyfin package, so I'm not sure where it all began.

Is there anyone who can help me understand where the problem is and if it's possible to fix it?

Many thanks!

[Berek]

Hello everyone, while trying to fix this issue, I stumbled upon this excellent topic https://forum.jellyfin.org/t-lg-tvs-no-longer-working that pointed me to the culprit of the sudden malfunction of Jellyfin on my LG C1. It was the "Modern Compatibility" setting I had set up at the "TLS / SSL profile level" section on my Synology NAS.

However, since I didn't want to lower my security level, I decided to connect my TV to the internal IP address of the NAS instead of using the FQDN I use from the Internet, and I was able to regain access to my videos from my old LG C1.

However, I still don't understand why this setting has made the TV stop streaming from the NAS. From what I've read online, the TV should support TLS 1.3 and modern ciphers (in fact, if I load the NAS login page via HTTPS, it works); however, this wasn't happening when using the Jellyfin native app.

Strange... anyway, I've solved my quest, and I hope this could be of any use to anyone in the same situation I was in.

Bye!