Thanks for the implied offer to help. The maps wouldn't load because the installer reported that there wasn't enough space on the device. They only require 9gb and there is 13gb free. These maps are supposed to be compatible with the 830, but apparently they didn't try to install them on a 830 for the U.S. market. The instructions say not to delete any of the maps that are shipped with the device, but my guess is that will be their recommendation.

I sent him the link to the bike specific osm maps for France, but I think he's too annoyed with Garmin to go that route.