Here is my viewmodel I am working on. I am trying to enable animations to play for it.
I have both of the Arms motor6D to the Root, and I have the Gun Motor6D to the Root, but for some reason it dont wanna rotate or move in moon animator.
the only thing i can think of is to check if the parts are anchored or not 
Try making everything in the view model visible. Moon Animator may be trying to rotate something else instead of what you have intended for it to rotate. Also, please set everything to be unanchored if not already like @Gamemaster712Z said as it does affect if the part has visibly rotated or not.
