[olympus]

The problem is that the Google plugin is not adding the right extention on all the file names.
The file names should end with ".strm"

Instead SOME of the extension end with ".mkv""
Solution, rename the extensions to "mkv.strm"

This is a bug.

Yes this is a bug, Kodi probably tries to play it like a normal file.
I haven't noticed it because I have my own script that remanes the files, I use it for my local files too.
I don't rely to this add-on or any add-on for my renaming needs, my metadata needs etc.
Create an issue on Github, this is the fastest way cguZZMan to know about it.
Because Github will send him an email about the issue.