You can recover your system in the following ways:
Exporting recovery keys — It is still possible to export the recovery keys from the source server by selecting the system and exporting the key or by providing the keycheck value.
Administrator recovery — The policy of the destination server will not be enforced on the system in a failure case. Administrator recovery is therefore only possible from the source server.
Repatriation of failed systems — If a system fails the transfer, transfer the system back to the source server - policy enforcement will start again until the problem is identified and solved.