When I run my project the the gambas3 IDE in Debug I get the following error:

GtkDialog mapped without a transient parent

And the app won't run in Debug

The error doen't happen when I run standalone executable. I'm calling dialogs from within the main Form_Open() method.

I'm running the IDE in Linux Mint 19 Cinnamon 64 bit in VirtualBox

Can you put up some code so we can see the error.

I just created a button on the main form for the method that calls the dialog. Fixed