Unfortunately you do not indicate what type of subtitles you're referring to.
BSPlayer has no problem whatsoever to play subtitles like SubRib .srt and MicroDVD .sub (text-based subtitles).
You can check if a subtitle-file is text-based by loading it in (e.g.) Notepad. Is it readable or rubbish?
You can perhaps find your subtitle e.g. in .srt format on one of the subtitle-sites as mentioned under item 9 of my
Help to Help post (link hereunder)
Please report back.