Problem with adding instrument favorites in 1.5.3

I just installed some new VSTs from Frozen Plain, and did a rescan of the library (Windows 10, v1.5.3 of Unify STD). I wanted to add them to instrument favorites, so I went into that dialog, instruments was already checked in the dropdown, and I saw my favorite instruments (about 10). I created a new subset, named it Frozen Plain, and had an issue that nothing happened when I pressed Enter. So I clicked the (X) to close it and Frozen Plain did appear in the subset list. I then searched for Frozen Plain and found the instruments, but "Add" was not active, and I could not add them to the list. So I quit Unify, and when I went back in, all my Favorite instruments were gone.

I have backups of the Unify files. Which one do I need to restore to get my favorite instruments back?

The favorite effects are still there.