Thread: "Cannot unlock maps" error after reboot on 3790T

Originally Posted by trenat

Thanks for that catymag, unfortunately I don't have a full backup of the files prior to this so I'm guessing replacing isn't an option. Any other thoughts most welcome

If you loss .gma or .unl file and you need that map.
You can copy the map to computer --> Unlock with Fast IMG unlocker2.1 --> Put it back to Nuvi. That's it.