Error during forest recovery process "Backup registration database error occurred: Operation must use an updateable query"
This error occurs when launching the FR Console without Elevated Permissions.
This is Recovery Manager for AD Forest Edition product defect.
Launch the FR Console via "Run As Administrator" to open the Forest Recovery Console.
Defect ID "TF00167088" has been logged. Waiting for fix in a future release of Recovery Manager for AD Forest Edition
I could not replicate this in my lab.