We're currently aware of an issue that causes Backups to not function correctly over FireWire connected RM mixers. Listed in the UC Release notes. ( Link )
Currently, only network connected mixers can complete the backup / restore process.
If UC is connecting over network and the process is still not completing, then you should attempt a Firmware Recovery / Reset and test the feature again.
NOTE: You will need to save any scenes / presets by hand to a computer / iPad as the reset process clears all mixer memory. Instructions for both below.
Scene Management Overview Article Link
Firmware Recovery / Factory Reset Process Article Link
If you still have further issues, contact Tech Support via Support Ticket, and they will help you figure out what's going on.