I was digging deep into my backup history and run into this problem.
I select an old file in the top half of the window, then I check a file in the bottom half.
When I click DIFF, slick complains that it doesn't have enough versions of the file.
I think that its date comparison is wrong, or maybe the message it gives is just wrong.
If I select a file change dated 10/31/2012, then I choose a file that has only been modified after that date (starting on 6/25/2014), then Slick should have nothing to complain about.
If slick feels the need to complain here, then instead of complaining "not enough versions" (which in other contexts - like version control - usually means that there are 0 or 1 commited revisions), it should say something like "There are no changes to this file older than 11/31/2012, would you like to see all of the available changes?"
(NOTE: The message oughta have the actual date instead of the generic text "the selected date")
Or, it could just say nothing and go ahead and open the versions diff window.
