I have the same problem. Did you find a solution?
Synology boots up and its written, that it is recoverable. I can only choose to recover. It then installs DSM and reboots just after a few seconds. After the reboot, its the same screen again, only "recover"...
I am in a loop - has this something to do with the MAC address? I used the MAC address shown in this tutorial (00:0C:29:FD:75:B1) -> i configured it in grub.cfg and in the VM in ESXi.