vCenter 6 FT Multi CPU

Hi there

I'm messing around with a trial of vCenter 6 Standard with some ESX hosts running vSphere 6 Enterprise Trial.

I'm trying to enable FT on a test VM that has 1x Virual CPU and 2x Core's, so in essence 2x CPU's. When I try enable FT it keeps throwing the error "The virtual machine has 2 virtual CPUs and is not supported for Fault Tolerance".

I've looked at the enable license features of the ESX hosts and they all state "vSphere FT (up to 4 vriaul CPUs)

Any idea what's cause it to fail with this error message?

Thanks

Andy