Hi Rikard,
thanks for the reply , but it’s a browser-related problem. Everything works now, but the button for fetching the address coordinates does nothing when clicked in Mozilla Firefox (tested with version 44.0).
I’ve also tried to use a fresh Firefox profile (default settings, no add-ons), but same problem.
Only Mozilla Firefox has this problem. In Microsoft Edge the button works.
After installing WP Google Maps the widget is shown now, but still the address/location button is not working.