
Freeware Trialware = Download Free software but some parts are trial/shareware. RECENTLY UPDATED = The software has been updated the last 31 days. NO LONGER DEVELOPED = The software hasn't been updated in over 5 years. Type and download NO MORE UPDATES? = The software hasn't been updated in over 2 years. Version number / Beta version number / Update version number and when it whas released. I'd appreciate it.Explanation: NEW SOFTWARE= New tool since your last visit NEW VERSION= New version since your last visit NEW REVIEW= New review since your last visit NEW VERSION= New version Latest version In that case I'd like to take a look at the file in question if you're willing to upload it to my file server. If that doesn't help either, I'll be out of ideas of what you can try. That way a guaranteed fresh version of the cache & settings will be used. Just take the portable version, extract the 7Z archive somewhere and start the GUI from there. Doesn't matter if you've currently installed it.

If that doesn't help, one more thing you can try (again on Windows) is to download the portable version. On Windows you can delete the cache folder while the GUI isn't running & try adding the file again. One thing that might be a problem is the file probing cache. Using your identification results to fake them on my end (meaning I've modified mkvmerge to always output exactly what you pastebinned no matter which file I chose) I cannot reproduce this issue, neither on Windows nor on Linux, unfortunately. Well, there are a couple of other potential reasons, but let's start with the above. The thing is, though… for SSA/ASS in Matroska there are no additional requirements that mkvmerge checks.

Are both tracks present here or again only one? On Linux use mkvmerge -J yourfile.mkv which will output a JSON representation of the interpreted content, same as the GUI's multiplexer tool would do.On Windows use mkvinfo or the GUI's info tool to inspect the file & compare that with what you see on Linux with mkvinfo.For some combinations of container & codec types certain tests are done, certain requirements must be met, otherwise mkvmerge will simply not list that track. See this FAQ entry for some more details, though the most important difference is that mkvinfo doesn't interpret what it finds whereas mkvmerge does: it'll only list tracks it is reasonably sure it can mux. Next, you're actually using two different tools here: mkvinfo on Linux and MKVToolNix GUI's multiplexer tool on Windows, which is roughly based on mkvmerge's interpretation of the tracks in a file, not mkvinfo's. Please make 100% sure they're absolutely identical.

The first thing that comes to mind is that you aren't actually reading the same identical file from both OS.
