what if the update completes and I can't sign in?
I completed the Catalina upgrade from the App Store, but now when I log in the wheel just spins and it doesn't launch.
Mac mini, OS X 10.11
Question marked as
Try booting into Safe Mode (How to use safe mode on your Mac - Apple Support) by booting with the Shift key held down. Then reboot normally and check again.
NOTE: Safe Mode boot can take up to 10 minutes as it's doing some system cache cleaning, volume verifying and directory repairing.