Application Crash problem on second time click on Menu Arrow of QToolButton

[Dong Back Kim]

Obviously, this is a out of range assertion failure so it means you are accessing an item in a list with invalid index. Since you are saying "if Nothing is selected from Menu list", it means there is no such list at all so it sounds like you are trying to access a index of null object? Are you sure the error is from the codes you provided because I can't think of any index out of range failures from the codes. I might be wrong... =(

Regards,