Strange msg

Hello

I attach a sphere collider and a rigid body to a child of a weapon but I get the error message

“Quaternion To Matrix conversion failed because input Quaternion is invalid {-0.195852, -0.556301, -0.273804, -0.759746} l=1.000011”

Actually the game runs but it seems that the collision detection is somehow erratic

What does it mean that message and how can I fix it ?

Try checking these out:

https://www.reddit.com/r/Unity3D/comments/2tlm53/quaternion_to_matrix_conversion_failed_because/