Aloha!
Ok I think I did something wrong.
I have the OSM maps from the website
BBBike Extracts OpenStreetMap and I had downloaded a new one like I did a million times before.
After copying it to my SD card I must of done something wrong because my Garmin Nüvi 760 is now stuck in a bootloop.
No problem I thought, I'll just link it to my PC and restore the backup. Ehhrr no.... I ...