Hi Scylla,
I have been experiencing a freezing on CREV which seems similar to the one discussed on this page:
https://forumserver.twoplustwo.com/1.../index184.html
despite it should already be fixed. Despite its randomness, the most clear way to reproduce it is just change the focus to a CREV window (I usually have many of them opened, with slight different parameters, that I am comparing) and the window will freeze around 1/10 times for around 2s - sometimes enough to Windows show the "not responding" message. But there are "not responding" issues also when I am creating a tree, in a single window.
Actually I have this identical freezing due to a focus change in only one more program (from dozens I tested): the Poker Stars tables (no the Lobby, that never freezes). Actually was the PS software that brought my full attention to this problem.
Trying to fix this issue, I started updating my drivers and found that there is a way to temporally solve this problem: I just create a Restore Point in Windows (just that, no driver installation) and both programs, CREV and PS, immediately become free of any freezing, but only for around 30 minutes, them the problem returns, in both.
So, I recognize that probably there is something particular in my machine/Windows 10 (it is a fast one: i7, 16 Gb, NVidia), but there is also something particular in CREV and PS, because between dozens they are the only programs displaying this behavior.