I can't save my skins in library. I tried with more than 15 different skins and don't wanna save it. I only have alex and steve but even with that it can't duplicate that skins. 

I can change my skin only in minecraft.net but I can't save it for future changes. 

I tried turn down and turn on my PC and reinstall Minecraft but nothing change. 

Thanks for support and sorry for my English