Bug: Rhino Render gone bananas

Edit: This is caused by Bongo, and tends to occur when a constraint is broken. After that the entire model remains broken.

What is happening here? When I rotate in the perspective viewport the object flickers and at some angles it disappears. Using R5 SR13, Win10.

And, sometimes when I click objects they go hidden, and at next click they show up again. I suspect that this phenomenon has with Hide to do, but who knows.

This happens only in one certain file.

Edit: I’ve seen strange behavior before in combination with Bongo (which I work with in this model), so perhaps Bongo is involved somehow. I was rotating objects that were part of a IK-chain (although temporary removed from the animation) when the render went bananas.

Is there anything I can try as to make the model work as normal again?

// Rolf