Some users report experiencing Mac startup issues after successfully upgrading to macOS 11. So if you try to start your Mac and macOS Big Sur won't boot, stays on the loading screen, or you can't log into your account, These are the possible solutions:
- Try to force restart your Mac
- Check the power supply and connect the charger if it is disconnected
- Sign in with another account
- Boot into Recovery Mode and run First Aid through Disk Utility
- If none of this helps, boot into Safe Mode and try reinstalling macOS Big Sur.
