Hi! I've searched for this problem, but did not find one (similar) - I have set up that when I quit Photo Mechanic, the Cache gets cleared. And when I quit Photo Mechanic, the Clear Cache seems to stuck - I just get stuck in the middle of proces and I have to force close it. Especially problematic if I want to reset or shut down computer.
If I do it manually, from the Preferences Menu, everything is okay.
Photo Mechanic Version 5.0, build 18980 (60d39ba) on MacBook Pro (13-inch, 2017, Four Thunderbolt 3 Ports) running macos high sierra 10.13.
(nothing serious, I know, but it still bothers me)
Best,
Jure