Error in Active Directory Operations

Hi,

I am just trying to test the new 4.1 so installed it as a VM and now trying to join the ESXi to the AD, I get the following error : "Error in Active Directory Operations"

Also when I try to join the ESXi using the DC IP its says the domain name contains Invalid Character  Quite Puzzling...??

Also I have checked the Date and Time as well as DNS and Routing config.

All seems fine but still doesnt work.

Any help is Welcome.

Thanks