This error keeps appearing everytime I upload a custom skin

[Djur]

Does anyone know why I keep getting this error every time I try to upload a custom skin? It even happens with images from Google; I’m not sure if it’s an issue with the game or something on my end. 

(Also, when this happened to me, I joined the game and the custom skin i already had was suddenly gone.)

I'd recommend using Postimages: https://postimages.org/
Just upload your skin texture there, copy the Direct Link (the one ending in .png or .jpg), and paste it into the game. That's what I use, and it works fine for me