Got it sorted out. Even Dune Support put me on the wrong leg first. No need for index.srt at all.
The Vision in fact supports subtitles in multiple languages the same way with ISO and BDMV Folders. The problem they must be in the same parent folder as the main movie BDMV folder.
Example for Mymovies folder
Mymovies/
Mymovies/movie-1
Mymovies/movie-1.srt
Mymovies/movie-1.EN.srt
Mymovies/movie-1.ES.srt
Putting them in the movie folder itself:
Mymovies/movie-1/movie-1.srt
Does not work. Asked Dune to change this to keep folders and subtitles together.
Thank you
Sorry, I'm not sure i understand the example:
Mymovies/
Mymovies/movie-1
Mymovies/movie-1.srt
Mymovies/movie-1.EN.srt
Mymovies/movie-1.ES.srt
Can you please provide photo of actual folder to better understand?
Did they agree to change it so it be as in my attached photo?