Failed to create Switch "DockerNAT"

I found several topics regarding this problem, but I got a slightly different error message:

Error: Failed to create Switch "DockerNAT": Failed while adding virtual Ethernet switch connections.

Internal miniport create failed, name = 'CD5B4592-8365-449D-B0C7-2B7AAC1CF347', friendly name = 'DockerNAT', MAC = 'DYNAMIC': Invalid handle (0x80070006).

Can someone point me in the right direction?

Ok, I created a new Hyper-V switch with this command:

New-NetNat -Name DockerNAT -InternalIPInterfaceAddressPrefix

But now I am getting this error:

'MobyLinuxVM' failed to start.

Virtual machine 'MobyLinuxVM' could not be started because the hypervisor is not running (Virtual machine ID 5F915054-4F61-45C7-A4AC-DA99869DC52A).

Using the coreinfo command-line utility, I get this output:

HYPERVISOR      -       Hypervisor is present
VMX             *       Supports Intel hardware-assisted virtualization
EPT             -       Supports Intel extended page tables (SLAT)

What does this exactly mean?