I seem to have solved this by using option 3 (Reset Disks to non-RAID) against the Offline Member (port 2).
Then a reboot and windows started OK from the Port 0 disk and starting rebuilding the RAID array against Port 4.
I seem to have solved this by using option 3 (Reset Disks to non-RAID) against the Offline Member (port 2).
Then a reboot and windows started OK from the Port 0 disk and starting rebuilding the RAID array against Port 4.