Opening UFO files is broken in 1.3.19. It opens a multiple “The file is locked because you haven’t made any changes recently.” messages, even if versions is disabled. Sometimes clicking unlock or cancel works, sometimes Glyphs crashes, sometimes Glyphs freezes.
Version 1.3.19 (466)
Do you have the latest build? Opening UFO files works fine for me.
I just updated to 466 and the problem still occurs with files that open with no problem in 1.3.17.
I had to tweak the versions locking implementation to avoid overwriting of original .otf file.
What did you edit this file the last time?
The problem files have not been edited in over a year. If I generate a new UFO and open it everything works properly.