Unable to map disk to my VM

Hi,

This is a Windows Server 2012, Failover Clusters.

Using the Failover Clusters UI, I click on "Settings" on my virtual machine, select my SCSI Controller, and click Add Disk.

A create "New", VHDx, Fixed, on my shared volumes.

When the Wizard is over, I click Apply and I get an error "The disk is already connect to the virtual machine..."

I can reproduce using PowerShell:

New-Item -ItemType directory -Path C:\ClusterStorage\Volume20\vsvr-mx-store04\
New-VHD –Path C:\ClusterStorage\Volume20\vsvr-mx-store04\Store04CoveoExec01_Archive_Log.vhdx -Fixed -SizeBytes 50GB
Get-VMScsiController -VMName vsvr-mx-store04 -ControllerNumber 0 | Add-VMHardDiskDrive -Path C:\ClusterStorage\Volume20\vsvr-mx-store04\Store04CoveoExec01_Archive_Log.vhdx

PS C:\Windows\system32> Get-VMScsiController -VMName vsvr-mx-store04 -ControllerNumber 0 | Add-VMHardDiskDrive -Path C:\
ClusterStorage\Volume20\vsvr-mx-store04\Store04CoveoExec01_Archive_Log.vhdx
Add-VMHardDiskDrive : 'vsvr-mx-store04' failed to add resources. (Virtual machine ID
F3ED8D45-8E14-4CAB-B01F-D20EAAE1C37B)
Cannot add 'C:\ClusterStorage\Volume20\vsvr-mx-store04\Store04CoveoExec01_Archive_Log.vhdx'. The disk is already
connected to the virtual machine 'vsvr-mx-store04'. (Virtual machine ID F3ED8D45-8E14-4CAB-B01F-D20EAAE1C37B)
A parameter that is not valid was passed to the operation.
At line:1 char:68
+ Get-VMScsiController -VMName vsvr-mx-store04 -ControllerNumber 0 | Add-VMHardDis ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidArgument: (Microsoft.HyperV.PowerShell.VMTask:VMTask) [Add-VMHardDiskDrive], Virt
   ualizationOperationFailedException
    + FullyQualifiedErrorId : InvalidParameter,Microsoft.HyperV.PowerShell.Commands.AddVMHardDiskDriveCommand

PS C:\Windows\system32>