Unable To Save Skin

I just recently got Minecraft: Java Edition, but it doesn't allow me to save or duplicate skins. I can wear the defaults just fine, but can't duplicate. I've tried multiple different things but everytime it just says "Unable to save skin." It's not the one skin that's a problem because I've tried this with a bunch of different skins. I don't know if this is a bug, or if anyone else has this issue, but I hope you can help.

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