When attempting to use the Transfer tool and you receive one of the following notifications:
Before beginning Transfer Tool Warning:
If no available IP addresses exist on the target server, accounts on the remote server that use a dedicated IP address will not transfer.
After the transfer is complete, a Failed notification:
"cPanel User" has no IP address!
It means that probably one of the (cPanel Users) you are trying to transfer has a dedicated IP address on the source server. In contrast, on the destination server, you don't have any free IP address available. You can choose to deselect the dedicated IP at the bottom and proceed with the transfer.
We would advise reviewing the source, make sure it doesn't have the Dedicated IP address, and then reattempt the transfer to your destination server once again.
That is what is preventing your from completing the Transfer, you can find more details here: