RockLobster
King in the North
It looks pixelated when you look at it as an attachment in a post, but as an avatar it looks fine.
How are you saving it to you computer? Make sure it's saving as a .gif and not a .webp
Yep, it's saved as a .GIF, and I still get the same "Oops! We ran into some problems. The uploaded file must be a valid image." error