I received same message when trying migrate VM from ESX2.5 to esx3.x.
I boot old VM from Coldclone.iso cd and everything goes fine until I get to Destination Type where I get above error.
No option except OK is available, which gives me another prompt for ESX or Virtual Server Login with User name and Password.
I tried VC server or complete ESX server name to no avail.
I am using VMWare Converter 3.0.0 build-39557.
Cab anyone help?