I have spent the last 24 hours trying to restore my drive since reinstalling the new beta. I do not know what the source of the problem is for sure.
1) After the reinstall I discovered that there is a folder in the main directory called PREVIOUS SYSTEM. 961 Gigs in size with almost 3K items in it. I treid to delete it since I toght that it was no longer active or of any use. That was a huge mistake! You could put it into the trash but you could not empty the trash. Got two messages...Cannot be deleted because it id reqiured by the System...You do not have permission to delete it. Unlike the System folder you could actually change it to a read ond write by the administrator.However that did not enable deleting the file.
2) Once in the trash, getting it out caused problems. It left an invisible file that I could not delete.
3) Wentto the App Store to update an app but could not do it. The App Store App failed. DEleted the app that was to be updated. Went back to the App Stoore to reinstall the deleted app but could not, all the App Store would do was make one attempt afther the other to update an app that was not there.
3) Several other apps stopped working. Messages about corruption and parts missing.
4) Finally decided to erase SSD and reinstall from Time Machine. In Recovery Mode Disk Utility could not erase the drive. Attempted to restore from Time Machine. It took about An hour, then got a message the the Time Machine Recovery had failed. Was told to reinstall OS and then use Migration Assistant App to restore the drive. That failed too.
5) Finally I restarted from my Flash Drive installer and was able to erase the drive where Recovery Mode was unable even to unmount the drive. Then restored from Time Machine. Got message that it had failed and was told to reinstall the OS and try agin. When I reinstalled the OS and let the iMac restart all of the apps etc were there but all had to be reacivated etc.
6) Having finished all of the the PREVIOUS SYSTEM Folder remains and cannot be deleted successfully.