Yes, I've seen that this is already an issue. I just think it's ridiculous that you said this issue fix was a W.I.P. back in July. I've paid for a Realm for me and a close friend to play on and they proceed to get this "Restricted Skin," error. They've been able to join a few times but this is a reoccurring factor, including others trying to do the same thing. I don't know if you don't care or if this is difficult in general because it's cross-platform. But it's tedious and immensely frustrating.

EDIT: Also, the default skins are being used.