GameCube Simpsons Hit & Run

I am using the Dolphine emulator. I have downloaded Hit & Run from this site as ISO and from another site as NKIT file.
Both give an error message when I get to level 4 on the mission where you have to talk to Cletus while driving near the trailer park.
Is it an issue with the ROMs or the Emulator?
I find it odd it happens with 2 different ROM files unless they are the same file just in different formats.