A note we found this weekend.
When converting from a Virtual on HyperV to vSphere we used the builtin tools in vSphere. But we were doing the conversion over a VPN from 2 different domains.
Error at 1% with conversion server error stating Host Not Found just after a reference to the server name.
Found that it actually looks for the Fully Qualified Domain Name not just the domain name, so added the FQDN to the HyperV Servers Host file and it successfully converted. Unfortunaly the error log only showed the Servername so we had to trial and error to know it was looking for the FQDN not just the servername
Thought I would write about it because this is the second time we had the problem and had forgotten from the first time what we did to fix it.