I'm using external USB hard drives to backup my server (Windows Server Backup). These drives are encrypted by Bitlocker To Go. I configured the disks to get unlocked automatically, because they are swapped every Friday by an employee.
However, Windows Server won't unlock them until someone logs on to the server, causing the backup to fail:
The backup operation attempted at '2015-11-11T23:00:11.671366800Z' has failed to start, error code '2155348147' (The backup destination is not accessible because it is locked by Bitlocker Drive Encryption.).
How can I get my backup drives unlocked without user interaction?