Pink squares in one site but not in the other

My buttons on the menus of my game are showing up as pink squares in gamejolt but not in gd.games, anyone can help me on this one? I stretched them manually instead of scaling them.

Pink squares are an indication the image isn’t available or couldn’t be loaded. If you go into developer tools in the browser (crtl + shift + i), are there any error messages in the console panel?