That means there's a network problem confusing the Imaging Tool.
Are you using the latest edition
Utilities? An update was issued during the early season.
Disable (not just turn off) the Classmate wireless.
Ethernet to a switch, and from there to the cRIO. Make sure the Ethernet port isn't flaky.
Firewall off and all that.
Oddly enough, in a certain number of cases, ENABLing the wireless may actually help, too, so try it both ways.
You can always try Imaging from a different PC, too.