Must construct a QApplication before a QWidget

Question

Everywhere only just \"before QPaintDevice\" questions and nowhere is my error. So, here we go.

I need an extern QWidget to be able to get access to it from outside

Answer 1

Maybe not helping the former author, but others facing the problem. I simply got this error by mistaking a debug-library with a release one. So check your linker settings, if you are sure the implementation is done right (first instancing application and then using widgets).