ROM Hack Mario Kart ds Blackscreen problem

[TheZoroark007]

I have following problem:I ve managed it to insert 2. costume models and all work fine. Then i inserted an other one And every time I try Vs mode , the game gaves me a blackscreen(on emulator,It don t works on ds after hacking).Then I inserted a 4. Model and now Time chalange doesnt work too.Can somebody explain me why and how to fix this?I already cheacked the models, they are fine...