In mine, there is no line 65. Line 53 is the last for loop of the "doStuff" function, and is the loop which handles outputting object.arraysOfPointers[i]. The for loop before that is at line 43. That's the one which loops while 'i' is less than sizeOfStr (a variable which is assigned the value of object.str->size()). There is no reason why it should be accessing a NULL value.