Apple upgraded my public beta to 12.1 tonight which I assume is the release candidate. As almost always the VM died during the upgrade with Apple.GPU enabled and I had to turn the VM off and revert to SVGA to complete the upgrade. Once the upgrade completed I was able to go back to Apple.GPU and the VM booted, but after login I got a grey menu bar with a black screen. I could launch apps from the menu bar but the app screens flashed and disappeared after launching. The VM did shut down normally from the menu bar in this state.
I rebooted and got a screen the second time, but then got the Volume Hash Mismatch error please reinstall. I submitted a Feedback to Apple.
