revert ed78465973f6 ("detach rope if the Land[] vanishes") for now, some questionable/troublecausing parts there.
#include <QApplication>
#include "mainform.h"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
MyWindow *mainWin = new MyWindow;
mainWin->show();
return app.exec();
}