SuperFalcon-95
loading
I'm not going to give you a cientific research of why it happens, just tell you the basics. Sometimes Scratch fails to load a sprite (how I said, not going to cientific explanations) and quickly replaces it with a grey square and a black question mark. I already saw people worried about this, if this happened to you, you haven't been hacked. Reloading the page should make it disappear. Hope this helped you! If not, tell me and I might search up for another solution.
And yet this still hasn't been fixed…