I have managed to update the favourites from my old map using djc151084's tutorial which worked a treat on the internal drive which has map 850.2820 with navcore 8.351.
However, on my SD card I have map 845.2649 with navcore 8.369. When I try to use the "Operate my device" feature via Tomtom Home, I receive an error message stating that the feature is not supported on my device.
Any suggestions please?