Just discovered this last night when trying to open a BIAB/Logic project I hadn't worked on for a while. I don't know what the specific problem is because Logic just goes away with a debug screen. So, if you use Logic and are considering upgrading to the Monterey public beta, maybe hold off. I have a spare Big Sur iMac to use, but if I didn't I'd be stuck just hoping Logic or MacOS fixes this soon.

========

UPDATE: The problem was EastWest's "Spaces" and "Spaces 2" reverb plugins. Removing those from my system lets the documents open, so I can use another reverb.