I decided to check out the Safari Technology Preview but when I found out that the 1Password extension (no, not even the beta one) wouldn’t work there was little point in continuing as I rely on that for any passwords.
I uninstalled the Tech Preview via App Cleaner and Uninstaller and one folder couldn’t be removed. The folder name started with
com.apple.SafariTechnologyPreview and I removed it manually via Finder which put it in the trash. When I tried to empty the trash it would complain that the folder was in use.
I tried rebooting in safe mode (hold down the Shift key while booting) to disable just about everything with no luck. The Mac was still complaining that the file was in use. I then tried the same experiment via booting into single user mode (hold down Command-S while booting) so I could perform the same thing as the root user. No luck there either as it gave more cryptic complaints.
This folder contained a file named
SafariFamily that was the problem. I found this page where the person had the same problem and had a solution. I had to disable SIP (System Integrity Protection) via the Mac’s recovery mode. Recovery mode requires restarting the Mac and holding down Command-R while until the Apple logo appears.
Once in recovery mode I had to open up the Mac terminal app (via the menu) and run the command
After that I restarted and that finally allowed me to delete the file. Then I had to reboot again into recovery mode again to turn SIP back on via
csrutil enable. Another restart and I was back in business.