Time Machine Error Code 92
Well, something happened to my MacMini as I tried to login this morning and I was unable to input my password (the box just would not show but the screen saver was still working). I restarted and everything came back up but my Time Machine was failing with Error Code 92 (two separate backups on two separate external drives). So I read through various threads and one referenced manually deleting the local backups. I didn't go that far, so let me explain what I did that worked for me.
First, I removed both external drives from Time Machine. Then I opened each drive via Finder and deleted the last entry file that said it was IN-PROCESS (open) and all the previous hourly backups and also the latest two daily backups. For me, there were 12 hourly backup files, and then the rest were daily files (reading from the bottom up or most recent). I just made sure all the hourly files were trashed as well as one or two of the most recent daily files. I essentially deleted all backups going back 3 days. Then I ejected the two drives via finder and then unplugged the drives from the Mac for a minute.
After that, I connected one of the external drives back to the Mac, then added the drive to Time Machine and did a "Backup Now". It processed as expected, and successfully backed up. I then connected the second drive and added it to Time Machine and it's running again.
Not sure if this procedure will help the rest of you, but it worked for me. I just didn't want to lose all the backup files using that other procedure. It seems that whenever Time Machine is interrupted for ANY reason and cannot continue, the process fails. It leaves one backup file open (in-process) and there are "links" to the previous hourly files as well as at least one or two daily files. Once those are cleared, Time Machine will figure out the last complete backup and restart from that point in time. At least, that's what I'm seeing. Hope it works for at least some of you.
Mac mini 2018 or later