Same problem here.---MBP 16" 2019 What seems to solve it for me : "Safe Mode" Open terminal> run "brew doctor" Your output should provide you with enough information. for me the problems were: 1)broken symlinks with python library , solved by removing symlinks then run "brew link python" 2) run "brew cleanup" 3)Xcode 11.6 , removed and installed v12 4) run "softwareupdate --all --install --force" After this my system seems stable somewhat on beta 5. Still dealing with the issue that CLT is not supported in this version.