Subtitle does not display correctly

[ahmad]

i was using ASS subtitle so by select All Complex formats

but is there a way to make this the default instead of select it for every client that use mt server

Sadly there's currently no way to make this the default for all clients.

Since you're using ASS subs, the screenshot of your issue indicates that the file trying to show the subs doesn't have access to the sub font files for the Arabic letters. Therefore, it's just showing everything with a box since it doesn't have the actual info needed to display them properly.

Most likely when you selected the option to burn in all complex formats, the fonts were pulled from the video file and used to burn in the subs.

the wired thing about my issue is some animes or series and movie in general that come with embedded subtitle work out-of-box but when i try to use external subtitles i face this issue 
so is there a way i cloud config fonts in jellyfin, as i search about this topic i did not find anything helpful