Modding Help - Paint Animations

I am trying to add in some mods that include a new paint undercoat and paint finish line.

I can research the slot and tech, add the slot in no problem, link them together in the production line, but I can never get the animation to change the base metal to primer, and the primer to finish paint.

If i change the slot sub task to paint_undercoat instead of the new slot name [paint mod 1] the game crashes once a car enters the slot?

Any help would be appreciated.