Hi all,
Just installed the update to Crossover 20 earlier, and then installed Steam and Fallout New Vegas Ultimate edition smoothly and all seemed fine. I am running on a 2020 iMac 5K, 3.8 GHz 8-Core Intel Core i7, 32GB RAM, AMD Radeon Pro 5500 XT 8 GB with macOS Catalina 10.15.7.
All started very smoothly: game launched and began a new game. Opening video/cut screen played fine and displays & audio was great. But once the gameplay loaded past the usual FNV loading screen and you wake up in Doc Mitchell's house, the entire screen is bright green. I still get game audio playing just fine, and I am able to interact with DLC loading alerts and I see the item inventory graphical notifications. Eventually when the character creator screen starts, I can see it barely, as if a strong bright green overlay has been placed over the game.
Not sure what is going on. I noticed it both when playing in fullscreen or windowed. Game was set to Ultra graphics level, as that's what it automatically set itself to when first installing? Should I try at other graphic settings? Any other ideas?
Here's a screenshot: 
Thanks!
William