Symptom
During the backup copy operation, the registration of a virtual machine fails with the following error:
The Operation is not allowed in the current state
Cause
The ESX server which hosts the virtual machine is in the maintenance mode.
Resolution
Before initiating the backup copy operation, ensure that the ESX server is not in the maintenance mode. If you are performing an inline backup copy, before initiating the IntelliSnap operation, ensure that the any host involved in the backup, is not in the maintenance mode.