For the last two years a problem was coming up occasionally with some users, that only the top left area of the map is displayed, and the rest is not loading:
Thanks to the analysis of Martin Stiel in a comment and Victor Ewert in issue 81 it seems that this can be traced to a problem when running the application on a high resolution display.
Alas I cannot reproduce this as I have no hardware with a resolution that might be high enough. So if you have this problem you might try the solution that Victor mentions in the issue linked above: start the application with -Dprism.allowhidpi=false.
So currently I cannot support this as for em this problem is not reproducible, But I’d be glad for feedback or any new information.