Thanks for your post.
If SQL Backup Agent and SQL Server's security accounts cannot contact a domain controller to get the security ID for the SQL Backup Agent's account, you will get this error.
The most common reason for this is that the SQL Backup Agent is running as a local service, which does not have permissions to access the domain controller on the network. Changing the SQL Backup Agent to run as a domain account with sufficient permissions to access the domain controller should resolve the problem.
http://documentation.red-gate.com/display/SBU7/Permissions
Hope this helps.
If SQL Backup Agent and SQL Server's security accounts cannot contact a domain controller to get the security ID for the SQL Backup Agent's account, you will get this error.
The most common reason for this is that the SQL Backup Agent is running as a local service, which does not have permissions to access the domain controller on the network. Changing the SQL Backup Agent to run as a domain account with sufficient permissions to access the domain controller should resolve the problem.
http://documentation.red-gate.com/display/SBU7/Permissions
Hope this helps.