What system version are you currently running? If it's any version of Catalina boot into Safe Mode (How to use safe mode on your Mac - Apple Support) by booting with the Shift key held down, download and apply the macOS Catalina 10.15.7 Combo Update.
NOTE: Safe Mode boot can take up to 10 minutes as it's doing the following;
• Verifies your startup disk and attempts to repair directory issues, if needed
• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)
• Prevents Startup Items and Login Items from opening automatically
• Disables user-installed fonts
• Deletes font caches, kernel cache, and other system cache files