@fogofwar said in "Operation not supported" tftpboot failing - please help:

Only one problem now that we got past that I am getting this error about “No configuration method succeeded” but only on a VM. I will have to look at that next.

This is only on reboot I am fairly sure! Shut down the VM completely, bring it up again and PXE boot will work nicely. This is a known bug in virtualbox.