Problem installing maps on device using latest Basecamp version

Unfortunately the latest Garmin Mapinstall is corrupt, they released a buggy update. You'll have to downgrade Basecamp to 4.6.2. See https://forum.openstreetmap.org/viewtopic.php?id=62468

If you have, or can find the map in .img format just transfer it to the Garmin folder. Do not put it in the wrong place it could cause problems. I like to put map.img s into a Garmin folder in the micro SD using a card reader. Then put the microSD into the device, it's safer

I have the same issue. Installed the latest Basecamp version and thereafter cannot install existing (and new) maps (completely visible in basecamp) via Basecamp Mapinstall on the Garmin Etrex30. As an example: After installing France, complete, there is just one tile of 137 loaded on the Etrex. I will try to downgrade Basecamp to 4.6.2 as suggested above and inform here accordingly if succeeded (or not).

As advised:

1. I have completely removed the latest Basecamp version 4.7.0.
2. Runned CCLeaner to get rid of any unwanted registerlinks (if)
3. Installed Basecamp 4.6.2. which I downloaded from http://www.gawisp.com/perry/mapsource/
4. Luckely, after a while, all existing stored Routes, Waypoints and OSD-Maps re-appeared as normal.
5. Succesfully runned Mapinstall to install all tiles of the selected OSD map on the Garmin device.

@ ligfietser: Thanks for the guidance.

Don't use Basecamp to install the card. Donwload the zip file from OSM, unzip it and copy gmapsupp.img file to your garmin.