I've seen similar posts to this problem, but found no workable solutions as yet.
I connect edge 1000 to Garmin Express. It said (some time ago) a map update was available (for the UK). I then try to update the maps and the install fails: "there was an error installing the update".
When powering up (with or without a SD card(, the device then says "cannot unlock maps" - which is not surprising really, as the map install fails. This situation just repeats over and over again.
I have tried to reinstalling the maps a number of times, formatting the SD card. Garmin support have advised to remove some (but not all - leave gmapprom.img file) GMAP files and the garmin device.xml file, remove the device from garmin express and then add it again, reconnect to it, reinstall maps. I have done this and the reinstall fail just keeps reoccurring.
I'm basically left with a unit that has no map functionality at all. Is there a master reformat or something that you can do? I have reset the device a number of times already