I have installed RT 5.7 on my desktop computer running Ubuntu 18.04.3. My image files are on a second hard drive (/media/steve/500GB/Digital Photos). The HD is mounted.
I do not find a way to get to my image files through the RT File Browser-Folders. I do not see the media folder.
If you have it mounted in that path (/media/steve/500GB/Digital Photos), could you change it to somewhere inside your home folder (perhaps in /home/steve/Pictures/Digital Photos)?
That way you won’t have to deal with permissions to access a root folder, and RT will show it inside your Pictures folder.
Paperdigits, I saw your recent post about overriding the sandboxing mechanism on a per application basis. It sounds like the same issue I have. I’ll get with a buddy that knows command line to try it.