Been getting a few folks with same issue - system won't boot.
Root cause is allowing the myServer controller to be power cycled. Either intentionally or inadvertently (like from a power outage).
This is Russian Roulette. Eventually if power cycled, the Raspberry Pi will be in a Write to Drive cycle and if power is removed...the boot sector of the boot drive will get corrupted and will not boot again.
To prevent: Ensure myServer is on a UPS. Highly recommended one that can be monitored by myServer so when the battery gets drained myServer's Automation Rule can gracefully shut itself (and other stuff) down.
Good cable management - don't trip on the cables!
And the real issue - power cycles don't fix things....they only make it worse. So, put a HDMI monitor on the controller and a wireless keyboard mouse and GRACEFULLY power restart the system. Or use the myServer Terminal Client window from a PC on the network, log in and do a "sudo reboot" to gracefully restart the system.
Get lazy and you will get bitten!
If you are unlucky, here is a fix
allonis.com/support/documentation?view=category&id=166
or mail the controller back to Allonis and we can rebuild it.
Power cycle issues are not warrantable.
Keep backups of your systems on a separate drive, ideally in a separate place (like all your important digital content).