The below warning may occur when backing up a DC in a collection where the "Ensure Forest Recovery Agent is deployed" option is selected:
"Failed to retrieve the product information from the Forest Recovery agent package file 'C:\Program Files\Quest Software\Recovery Manager for Active Directory\RecoveryAgent64.exe'. The system cannot find the file specified."
This may occur if the Forest Edition product was installed on top of the base Recovery Manager for AD. The RecoveryAgent64.exe file should be in a Forest Edition folder.