Why am I having to restart Unity every time I add a new locomotion system.

This is going to need more detail so here it goes. I am trying to create a dummy object that will be used to house the animations and logic for players and NPCs. There is no problem with that. The top level object is just a container for everything, this included the mesh.

In order to get the locomotion system working with the mesh, and having the least amount of head aches, I created a prefab that I can just swap the mesh on. From there, I created a custom GUI Editor GUI button that adds the required components to the mesh for the locomotion system. The locomotion editor class creates the groups that I need for my leg controller needs. From there all I have to do is hit "initialize."

This is where the funny part begins. If I do this and then start the game, I get a nullreferenceexception. However, if I restart Unity, and then hit initialize, there is no issue.

My question is, what would cause this, and has anyone found a solution to this?