Hi Toni Carrera,
I understand that you are experiencing boot errors when attempting to start a Hyper-V virtual machine with a Western Digital MyCloud 6TB drive attached as a SCSI physical drive. This issue seems to occur only when the drive is connected, as the VM boots perfectly without it.
First, it's important to confirm that the VM's SCSI controller is capable of properly handling the attached drive. Sometimes, certain SCSI controllers may have limitations or compatibility issues with specific devices. You can check the settings of the SCSI controller and ensure that it supports the size and specifications of the Western Digital MyCloud drive.
Additionally, it might be worth checking the configuration of the virtual machine...