Did this really need to be treated as an error, rather than a warning? Maybe there's some really good reason to avoid this case, but per the error message it seems that PhysX is just going to fallback and use Discrete collisions in this case. So, it feels more like a warning than an error. After updating to 2018.3, I'm getting this a lot because of causes where I temporary set a Rigidbody to isKinematic = true. Now it seems that if I ever want to toggle isKinematic, I'll also need to change the collision detection mode, and remember what it was before I changed it. This seems like an unnecessary hassle if PhysX is just going to not really care anyway. Anyway, is it possible for Unity to treat this as a warning instead of an error? Maybe that doesn't seem to matter, but with this treated as an error it causes unit tests to fail if this condition occurs.