Rigging robots - forklift - explodes on simulation

I am just reading and following the rigging robots documentation here 5.5. Rigging Robots — Omniverse IsaacSim latest documentation

I added a ground plane and physics scene and loaded the completed asset provided forlift_b_rigged_cm.usd. However when running the simulation the model explodes and flies off.

On the page there is specific

5.5.4.1. Troubleshooting Tip * If upon “playing” the simulation or after some movements, your robot explodes, check if any of the collision meshes are colliding with each other.

I know how to turn on collision meshes for visualization, but that makes it very busy and not very instructive for debugging. What is wrong here and how do I go about fixing it?