Panasonic ST50 subtitle/mkv/playing problems

Hello,

Today I've installed Serviio in order to stream HD content to my Panasonic ST50 plasma tv.
I am using the Panasonic VIERA ST (2011) profile.

I only use .mkv files.
SRT subtiles don't seem to work. Only on 20 out of 1000 movies.
Around 350 movies don't play at all. (Stuck after 2 seconds or only 4 frames are shown and after that a crash)

Do I need to post a detailed log on these specific movies?
Are there any other profiles I can use?

Thanks

[zip]

post ffmpeg -i of a file that doesn't play/crashes.

Thanks for the reply zip!

I''ve installed mezzmo and all files are playing correctly now including the subtitles!