Thanks for your feedback. I would suspect my .mkv file has an empty subtitle track inside. However, the .srt file that I downloaded from Open Subtitles has content - I opened the file with TextEdit and I can read all the subtitles in English, with timeframes that show when the text should appear in the file. Not sure why that wouldn't work in VLC...
How did you remove the pre-existing subtitles from the .mkv files? How did you get the external subtitles to work?
First of all I should say that my ext. subtitles were working fine as long as I manually select them. my problem was that it just wasn't auto loading the same named external subtitle file...
so since I don't know your exp. level on this subject I'm gonna assume that you don't have any exp. and start with very basics;
there is an "open file" command in the video->subtitles menu and that is the way of showing ext. subtitles manually..
did you try and success that way?
if you still can not see the subtitles you choose then it is most certainly your ext. subtitle file is the problem (even it looks right there might still be errors in the file that prevents vlc to interpret the file structure)
and if your problem is actually that you cannot autoload the ext. subtitle file as default action (just like me), then you should follow my steps and try removing internal subtitle tracks of mkv file(s) you have. in order to do this you will need some tools such as "avi mux gui" or "TS muxer" which I used in windows but I don't know if there is any equivalent for mac environment. and the process does not involve any encoding so its fairly easy and quick...
Although I don't seem to need to remove int. subtitle tracks any more ever since I switched to mac environment. the default action is to load ext. subtitle file here...