I was getting an error message like this:
Module DevicePowerOn power on failed. Unable to create virtual SCSI device for scsi0:0,
I later found out that the image was being used in VMWare Player and needed to be converted first. In this instance you need to download VMWare Converter (Link) and connect to your ESX box. It will convert and then transfer it for you.
VMWare has another way of doing it. Its listed as the source below.