The Operating System on the Recovery Manager for Exchange Server will need to exactly match (down to the Service Pack or Release) the Operating System on the Exchange Server where the Offline EDB file resided or was backed up from.
Example: If the Backed up Exchange server or where the Offline EDB resided was running Windows 2008 R2 the Recovery Manager for Exchange server would need to be running Windows 2008 R2. If the Recovery Manager for Exchange server was running Windows Server 2008 SP1 a Defragmentation would be needed.