Hello derailed Tom,
thanks for your notice. Yes, the videos are a recurring problem; since the pool of available ads frequently changes, there can always be some among them that won't work for some players, and unfortunately, there's much we can do about it.
However, you have quite a long list there; do all those videos just show a black screen for you, and nothing else happens? Because it can happen that the pool of videos is used up, in which case you should still see a fallback ad, but the player takes some time to load those.