Getting null pointer crash 4.1.1

Starting to use a property grid manager. I get the manager to display (with two different pages). I have a callback set for the on_grid_changed and have the event parameter. If I don’t access the event parameter, things appear to work fine. I can get selected page and other items. But when I access the event parameter, even in the debugger, crash. Nothing other than the 0xC00000005 error.

Clean installation, which i just completed today. The rest of the app works fine with panels galore and lots of tabs.

Thoughts on how to debug?


Hi cryptoref,

Are you keeping a reference to the event object outside the event chain? It might be a dead object and can cause your program to crash. (cf. A problem with Event objects)

To find out where the access violation occurs, try the following option:

$ python -Xdev -Xtracemalloc ‘’