Recently, me and my friend have been having issues with the skins. Everyone's (and our) skins are showing as Steve or Alex. I have tried to play in my own private world and have come to the same error, along with my friend. We have gone on multiplayer servers and others, only to reach the same problem. We have uploaded new skins recently, we shouldn't have Steve or Alex. My friend has had to go back until version 1.8 to see skins.

What can I do to fix this? I have never reached such a problem before.