Challenge
Over time, duplicate or outdated credentials may be saved in the Credentials Manager of Veeam Backup & Replication.
This article documents a process for reviewing and cleaning up the Credentials Manager.
Solution
No changes to the Credentials Manager account list are saved until [OK] is pressed. So, if an account is accidentally removed, click [Cancel], and the account will not be removed from the database.
More Information
One of the trickiest entries can be one that states "<Server Name> (<Job Name>)" and lists as "Guest OS credentials for Backup Job".
This means that the credential has been specifically assigned to that server inside the job settings under either of these locations.
Job Settings > [Guest Processing] > [Credentials...]
Job Settings > [Guest Processing] > [Applications...] > (Edit the specific server) > [Oracle] tab
For Veeam Agent for Microsoft Windows Backup jobs check the SQL tab next to the Oracle tab mentioned above.