Basically yes, I mean sending a copy of the VM files. OTOH if there are 3 such machines, I don't know. I thought it could be some peculiarity in the vhd header, footer or whatever, but if there are 3 of them, that's strange; perhaps it is a network issue after all.
I don't understand what it means "making a copy of the virtual machine on the same host and got the same error". If you copy, not convert, a VM, how can you get an NFC_NETWORK_ERROR?