SetUserData was recently removed in Box2D 2.4.1. I’ve also noticed some of my old code that used the
b2BodyDef method (I had forgotten I used that in the past) would no longer compile; previously it was just a direct
void* pointer without the issue I mentioned.
Instead of doing
foo->SetUserData(bar), now it seems the correct way is
foo->GetUserData().pointer = bar. (Source)
CLICK HERE to find out more related problems solutions.