I was testing out some games on an emulator called bgb, which isn't what I normally use (I normally use VisualBoyAdvance). Whenever I try playing any hacked games on it (even simple hacks where only the color palette is changed), it warns me about a bad checksum, though it runs the game completely fine anyway. For example, I tried playing the hacked Japanese DKL3 (that I hacked), where I changed the colors around, and it gave me this before the game started up:
Does this mean I hacked the game badly or something? Because when I play it, I don't see anything wrong with it. How does it know that I hacked it? And it does this with other hacks that I play, even ones that I didn't make.