Supply password or delete backups

[sb1815]

A SOBR backup was disabled for 10 months. I enabled it today.
When I run the job I get this error "Unable to continue encrypted backup chain. Supply password or delete backups, then try again"
In backups, under disk (encrypted) clicking the name prompts for the encryption password.
The password is not working and i don't need the old data.

How can I delete the backups to get the job working again?

The password was not changed, but we did upgrade from V11 to V12 since the last time the backup was run.
I have deleted all the old backups as far as i know to do.

what am i missing?

[sb1815]

I think i found a solution.

I cloned the backup job and ran the new job with the same settings as the original job.
The new job seems to be working and has already backed up the first 2 drives of the first server in the backup.
If this succeeds, I will delete the problem job.