I have a problem with subtitles, and I hope someone can help. They work just fine for some movies, but doesn´t show up for others. The setup is the same for all movies (external subtitles, both .idx and .sub-files). I can choose the correct subtitle in settings before starting the movie, but they just doesn´t show when the movie is playing. And as I mentioned, for other movies they work just fine - no problem. I run the plex media server on a Qnap NAS, if that might be relevant. I´ve tried looking in the forum for an answer to this problem, but have been unsuccessful so far.
Playing them locally works? Using VLC for example.
Yes, that works just fine. There is no problem when using VLC.
Try using Subtitle Edit from http://www.nikse.dk/subtitleedit/
Open your current subtitle file and save them as .srt type
Upload the .srt subtitle and remove the other ones. test and see.
Remember to name the .srt correctly. https://support.plex.tv/hc/en-us/articles/200471133-Adding-Local-Subtitles-to-Your-Media