My main.cpp? Never changed somthing in it. Was set up automatically:


#include "MainWindow.h"
#include <QApplication>

int main(int argc, char *argv[]) {

QApplication a(argc, argv);

MainWindow w;
w.show();

return a.exec();
}


I deleted some unused Widgets in my UI-File. Since then, the errormessage never appeared again - Happy about it, i won´t ask why.

But Thanx for your help