No Map or Trail displayed at all.

I added and activated the plugin.
After that added the shortcode to a new page and tried to showed a gpx file i recorded with locus map on my android phone.

The page only shows the spacer where the map should be, but thats all. It neither shows the map or a trail or anything else. I tried to add markers by itself and it just shows the same empty “box”. Even when i try it with the gpx file provided by the plugin author on the demosite, I get the same result.

Either there is something wrong with the plugin or some connflicts going on. Can someone point me in the right direction please?

Thanks

The page I need help with: [log in to see the link]