Force quit the installer, boot into Safe Mode according to Start up your Mac in safe mode - Apple Support and restart the Xcode11 install from there.. Then reboot normally.
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
![](https://discussions.apple.com/content/attachment/fef82bbf-f8ad-49a8-afd1-cfeef829e160)