Map not showing

[kaupanger]

Since Google changed their policy regarding the usage of GoogleMaps I use the offline version of RouteConverter. This version works with the OpenStreetMap default map. This was always without problems. The last time I used it successfully was 2 Jan. Since a couple of days however, I cannot see the map anymore. When I open a recorded track I only see the track, but no map, as you can see in the attached screenshot. I didn't change anything. How is this possible and what can I do to correct this?