vRA 7.2 "Cannot drop {software_component} onto "vSphere Machine"

Hi,

We are currently trialing vRA 7.2 and as part of that trial I'm trying to set up blueprints that will use software components. I've created a simple SC and a VM template that was prepped using the prepare_vra_template.ps1 to install all the required agents. The problem is that when I go to drop the SC onto the machine in the BP designer I get the error "Cannot drop {software_component} onto "vSphere Machine". I've added some custom properties to the machine

VirtualMachine.Admin.UseGuestAgent

VirtualMachine.Customize.WaitComplete

In the hope that they would sort it out but so far I've been unsuccessful. I also don't seem to be able to locate any other prerequsites for this that I may be missing.

Any help would be appreciated.