c++ debug assertion failed - c++

Question

I have a problem when I try to run this code
void MyClass::setUp(){
list->clear();
Iterator i = ctr.getAll().iterator();
while (i.valid()) {
list->addItem(QString::fromStdString(i.elem().getNr()));
i.next();
}
}
When I exit the function an error occurs:
Debug Assertion Failed!
File:C:\Program Files \Microsoft Visual Studio 14.0\ VC\ include\
xmemory0 line:106
Expression: "(_Ptr_user&(_BIG_ALLOCATION_ALIGNMENT -1))==0 " &&0
I am trying to iterate through a custom list
The Iterator class is this:
void Iterator::first(){
while (pos < ht.nrElem && ht.list[pos] == nullptr)
pos++;
if (pos < ht.nrElem)
current = ht.list[pos];
}
Iterator::Iterator(const HashTable & ht): ht { ht }{
pos = 0;
first(); // current will refer the first element of the list
}
void Iterator::next(){
current = current->getNext();
if (current == nullptr) {
pos++;
first();
}
}
bool Iterator::valid(){
return (pos < ht.nrElem) && (current != nullptr);
}
Car& Iterator::elem() const{
return current->getCar();
}

Answer 1

For one thing, Iterator::first and thus the constructor do not neccessarily initialize current. Second, in Iterator::Iterator(const HashTable & ht): ht { ht } does it mean that Iterator has a member ht , and the parameter is also called ht? It is a bad practice. Never call parameters of member functions the same name as class fields.