But i can tell you that i'm 100% sure that this is'nt a softmod issues. Maybe your wii drive (even if works correcrly with other discs) has some issues with this specific disc that the wiiu drive hasn't because is younger or for other reasons that we don't know.
And if it was a softmod issue, instead of the black screen you should see a message error after the disc loading that is a piracy prevention chack that says "error 001" or "error 002" but your games just crashes, is a reading erro, trust me