I made the import of courses as TCX file because this format contains (if used) turn informations. Export them from any source like strava or bikeroutetoaster etc... and then import them into the New Files Folder.
Rays explenation for the replacement of the basemapp with for ex. openstreetmap is simple and it works.
Did you extract the downloaded file from openstreetmaps?
Did you rename the file correctly?
Maybe the file size is too big?
Uploading gpx tcx files using Garmin Express Manual Upload doesn't work (as previously reported upload takes place then you get a cross marked on the upload).
Manually placing them in the Activities folder doesn't work.
Frustrated here - loads of stuff on Strava - don't want to recreate it all on Garmin Connect Maps.
Help appreciated here - how do we get the standard gpx/tcx files on the 520?
This is a screenshot of my Garmin folder:
https://pl.vc/1wn5g
I downloaded the maps from http://garmin.openstreetmap.nl/ and receive the eMail with a link to an download site -next screenshot:
https://pl.vc/4wf82 -> i used the yellow marked zip file
...and extract the file to my desktop or in a folder of my choice...
https://pl.vc/3mrz5 -> yellow marked is the extracted file....
Maybe you have to rename your file without the .img only gmapbmap