Runtime error

[nina1983]

Dear,

I'm implementing a QTreeWidget with drag and drop features.
The general elements belonging to the tree is setted with these flags:

item1->setFlags(item->flags() & ~(Qt::ItemIsDragEnabled | Qt::ItemIsDropEnabled));

Then only for the elements I want to drag I'm setting all these flags:

item2->setFlags(Qt::ItemIsEnabled | Qt::ItemIsSelectable | Qt::ItemIsDragEnabled | Qt::ItemIsUserCheckable);

It compiles and runs but when I try to drag one element I get the Runtime Error here attached. Really bad!!!!!!!!
Which could be the problem of such errors???

Thank in advance

Annalisa