SOLVED: Docker fails to start after upgrade from RC2 to RC3

From this
[11:22:00.264][HyperV ][Info ] VHD D:\Hyper-V\Virtual Hard Disks\MobyLinuxVM.vhdx already exists
[11:22:00.322][HyperV ][Info ] Creating VM MobyLinuxVM…
[11:22:03.615][NamedPipeServer][Error ] Unable to execute Start: Failed to create VM “MobyLinuxVM”:

I think the installer is trying to recreate the VM even if already there. I would clean-up Hyper-V (maybe even try to disable the feature) and let Docker re-enable the Hyper-V feature.
But that seems like a bug in the installer.

Also have a look here "DockerNAT": Instance MSFT_NetIPAddress already exists
Might be related somehow!