When attempting to restore a mail store to a Recovery Storage Group, you receive the below error:

Error
Error is produced: Completed status: Failed
Final error: 0xe000ff00 – Unable to restore some Microsoft Exchange components because one or more of the databases are currently mounted or because the Recovery Storage Group is not properly configured. Use the Exchange System Manager to check the configuration of the Recovery Storage Group and the mount status of the databases.
Final error category: Resource Errors

 Resolution

Carry out the below on both Backup and Exchange server.

1) Within the registry locate HKEY_LOCAL_MACHINE\Software\Symantec\Backup exec\Engine\ese
2) Create a new DWORD named ignore mount state
3) Set the value to 1

Carry out the above on both servers. On the exchange server you will need to locate the same location in step one but instead of Symantec you may see Symantec Backup Exec Remote agent or something similar.

Try again, if it does not work restart backup exec services on back up server and Backup exec remote service on Exchange Server