After upgrading to macOS Big Sur's update on 11/19/20, the login screen freezes intermittently, after entering the YubiKey login pin, requiring the MacBook Pro to be shut down completely and turned on again.
The YubiKey issue has been documented from a few sources.
- Reddit - MacOS Big Sur SmartCard Authentication issues
- Apple Discussions
MacBook Pro Configuration
- Two-Factor authentication enabled with a YubiKey 5C
- OS: macOS Big Sur, Version 11.0.1
- Device: MacBook Pro (15-inch, 2019)
- Processor: 2.3 GHz 8-Core Intel Core i9
- Memory: 32 GB 2400 MHz DDR4
- Restart the computer.
- Shutdown and turn back on.
- Reset NVRAM. See: Reset NVRAM or PRAM on your Mac
- Reset SMC. See: How to reset the SMC of your Mac
- Run Disk Utility's First Aid: No issues found
- Run Apple Diagnostics: No issues found
- Scan computer with AVG Antivirus: No viruses found
- Reinstall Big Sur from macOS Recovery
- Remove apps from starting automatically at login. Specifically, there was a Zoom app that I removed from starting at login. See: Add or remove automatic items
- Run in safe mode: The frozen login screen still persists intermittently in safe mode. See: How to use safe mode on your Mac