This is an issue related to some roblox update and to my knowledge doesn’t break anything in your game and a lot of people have gotten it including me.
Now to get to your issue, you haven’t exactly provided much for us to go with. Could you please provide us with some screenshots/anything else that could help?
It was because i named the ViewportFrame to hexadecimal so the script read the name as “ViewportFrame” instead of the hexadecimal name. All i had to do was to encode the hexadecimal name (not decode).