I ran into this freeze while changing my cache location (copy and pasted to another SSD). I thought the freeze meant I did it wrong (program didn't like the change), so I deleted the old cache selections and recached them. That worked, happy, everything was fine after a few hours of caching. When I played the game and returned to cache screen to cache more areas, it was frozen again. I would say for now, if you start from a blank cache, probably best to do ALL your caching in one session without exiting the caching screen, or you risk being frozen out of additional caching activity! I even let the thing sit for an hour to see if it would recover and be accessible, but no dice.
Paul