It's not obvious which particular framework you're using here (Rogue Wave?), but I think it may be possible to deduce the problem.
The key to decoding this assertion is understanding what incompatible iterators means. In general it means that you're trying to do an operation on a pair of items that don't refer to the same thing. For instance: (with standard library containers)
std::vector<int> v1, v2;
for (auto it=v1.begin(); it!=v2.end(); it++) { // <=== iterator incompatible
}
std::vector<int>::iterator it1=v1.begin();
v2.erase(v1); // <==== iterator incompatible
If you dig into the definition of the iterator types you have, then you should find that when the iterator is created it stores a reference back to the container it was created from. If you then perform an operation on two iterators (as in the first case above) then it can detect that they refer to different containers and hence aren't compatible. In the second case you have an operation on a container and an iterator, and so again it will assert that the iterator refers to that container.
In your case it appears that you're trying to remove an element from a container. The framework is asserting that the item isn't in the container (and in fact is probably in another). I suspect that you're deleting an item from the wrong container.