I’ve a Garmin Edge 810. When I try to use maps there’s nothing there but a triangle and zoom buttons. There’s no streets. I’ve gone to map information and that’s blank also so I can’t enable or disable?
This means that the device can't see any maps in the storage. Are you sure the maps are there? Connect your edge to a computer and tell us what you see in the Garmin folder.
I can see that a checksum file for the basemap is still present (gmapbmap.sum), but the map file itself (gmapbmap.img) is indeed missing. If you don't have a backup copy, then I don't know how to recover it.