I know many people suggest turning on ZTP bloom hack, but it can also cause problems for other games. If you have a black screen, try disabling or enabling it. I've solved issues with both Fire Emblem and Magical Melody by disabling it.
No one ever said it fixes all games, people suggest this because most of the time it will make a difference
I see it recommended more often than not. I'm not saying it doesn't work, I'm sure it does, but I since it's recommended on more, people might make the mistake of thinking it'll solve all problems. I know, I was reading these forums before I even started using Dolphin, so I had ZTP bloom on by default, and I couldn't figure out why I'm having problems. I just wanted to let new people know it works both ways.
I know for sure that Sonic games require ZTP Bloom hack for any graphics.