Had the "honour" of being one of the first to get the V56 firmware upgrade in late September, with none of the problems experienced on the earlier version, ................ until today!
Initially was working fine, then the continuous "Navigation Loading" screen.
After 15 mins, pulled over, switched off, locked car. On return before starting, removed / ejected the SD card, re-inserted it and then switched on, but problem persists. Now, when I switch-off I briefly get the old digital compass screen before the system shuts down.
Car booked in with my local dealer for Friday am investigation