This crash took me about 40hr+ to replicate and find a way how to eliminate it (unfortunately not to fix it). This crash occurred only on OS X 10.10, not 10.9, not Linux, not Windows.
Bug occurred in slightly modified QtTreePropertyBrowser where we have additional buttons for each property.
When any of these buttons caused property tree refresh, application randomly crashed. But when these actions were executed by buttons outside of the property tree, everything worked fine.
I updated methods from signals-slots mechanism to QEvent system. Unfortunately this didn't help as well. Next attempt was QTimer usage instead of QEvent or signal-slot to simulate real click. But also without any success.
With a lot of luck I finally found the reason for the crash. It's caused by erasing a property tree (and inner QTreeWidget) together with an active focus on this widget. Unfortunately I'm not able to fix it in the QtCore because according to callstack there is only some QModelIndex manipulation without any sight of what's going wrong.
The effective solution how to fix this wrong behaviour is to temporally set focus to another widget (or parent), clear the tree and set focus back to property tree. Unfortunately this solution doesn't work. Check part II of this article for better solution
If anyone know how to fix that, I will be glad for any info.