Unable to save skin/ unable to duplicate skin

I don't know what is happening, when I try to upload new skin to Minecraft it says "Unable to save skin" same when I try to duplicate it. Everything was fine until now, I hope you can fix this. I just don't get it, I tried everything and it still doesn't work what do I have to do? Please solve this bug for once and for all. Please. Thank you, I hope you read this.