Crash in QGraphicsItem::paint

Hi,
my Application is crashing in a custom QGraphicsItem paint Function.
I just have to execute
QImage temp(1000, 1000, QImage::Format::Format_Indexed8);
painter->drawImage(target, temp, temp.rect());

Then I get a QList::at crash because d was deleted and it generates an access violation.
Somewhere in
convertIndexedToARGB32PM(unsigned int * buffer, int count, const QList<unsigned int> * clut)