Create VirtualMachineNetwork fails - Error ID 27235

Hello,

I tried to create a new Virtual Machine Network, first by using the GUI, but failed with error ID 27235. So I tried Powershell directly, using the following command:

New-SCVMNetwork -Name "VMN_DMZ_DA" -LogicalNetwork "LN_DMZ_DA" -IsolationType "NoIsolation"

and got the follwoing error:

New-SCVMNetwork : Method not found: 'System.Guid
Microsoft.VirtualManager.Remoting.IVirtualManagerMethods.NewVMNetwork(System.String, System.String, System.Guid,
System.Guid, System.Nullable`1<Microsoft.VirtualManager.Remoting.VMNetworkType>, System.String,
System.Nullable`1<System.Guid>, Boolean, System.String, Boolean, System.Nullable`1<System.Guid>,
System.Nullable`1<Microsoft.VirtualManager.Remoting.VMNetworkIPAddressPoolType>,
System.Nullable`1<Microsoft.VirtualManager.Remoting.VMNetworkIPAddressPoolType>, System.String,

Does anybody know a solution?

Many thanks in advance,
Markus