Problem: Aperture needs repairs. It can be simple sticking (that can be ok for video), or worse. Ask seller. If you use Kipon adapter with aperture it can be ok.
Ad it si still available. People are generally afraid to get something with problems. But, really, if you search for fast EF mount glass for m43, aperture in Canon glass is irrelevant as you can't control it anyway, only using Kipon adapter.