It seems to be an IDX type (or something similar), since it defintely isn't a standard text-type subtitle, and file size is ~1.85MB (usually text based subtitles are only few KB).. To know the file type (not only the "Subtitle File" info, but the real extension), enable the files extensions to be visible (open a folder in Windows Explorer, select from the menu
Tools, then
Folder option,
Display, and UNCHECK the option "Hide extensins for common file types").
One more thing: you don't need to pay for the Pro version to enable subtitles features (only the Edit Subtitles need a registration fee, but it's not your case).
