Loading back-up on RB1100AHx4 Dude Edition

I’m attempting to move our dude over to the 1100ahx4 Dude Edition and I’m not able to get it to load. I exported a back-up from “The Dude” and I’m attempting to “restore back-up”, however keep getting the error message “file not found”.
This is a major jump for us as we are currently using The Dude 3.6 and I’m attempting to get the new server running on 6.44.2