Hi, are you using 32-bit Windows by any chance? It looks like there's a problem building in that version which we're looking to fix in GB Studio 3.0.1 soon.
Eject the engine, by hitting the game tab, advanced, then eject, it will ask for you to eject it twice. And then run the game like normal should fix it. You may have to do this again when you exit out of gb studio.
