_ITERATOR_DEBUG_LEVEL = 0 (in release mode)

_ITERATOR_DEBUG_LEVEL = 1 (in release mode if _SECURE_SCL is defined)
_ITERATOR_DEBUG_LEVEL = 2 (in debug mode)

Code runs in DEBUG mode because OpenGL libs are compiled in DEBUG mode. Can't set _ITERATOR_DEBUG_LEVEL = 2  in Preprocessor because _ITERATOR_DEBUG_LEVEL = 0 in Release mode