Error
Instance “servername\instance_name” not found!
Skip backing up “servername\instance_name (SQL SERVER xx.xx.xx)” (Instance does not exist)
Cause
After 9.11.x.x rolled out, we saw some issues where the Windows user authentication for the backup set became disabled. If the SQL instance uses Windows authentication for login, an error will be shown during the backup.
There is a known issue affecting some clients.
Fix
If the backup set uses Windows authentication, reenable that in the backup set settings and ensure the Windows login is correct.
If the backup set uses SA, update the SA login password on the backup set.
Run a new backup.
