There are no available servers running the Microsoft Exchange Mailbox Replication service.
Mailbox move requests are handled by the Microsoft Exchange Mailbox Replication service which is part of the Client Access server role. In order for a move request to be successfully created at least one Client Access server within the same Active Directory site must have a running Mailbox Replication service.
Start the MRS on at least one Client Access server. If it will not start the issue may be that the Net.Tcp Port Sharing service is disabled on the Client Access server. If that is the case then run the following command on the Client Access server in a PowerShell window.
PS C:\> Set-Service NetTcpPortSharing -StartupType Automatic
Restart the Client Access server, or manually start the MRS, and then retry the move request again.