Is this a bug of ue4?

i just created a scene and added a matinee animation to camera
and play the matinee animation when event begins
however, every time i play the level and during the animation time there is a ball without any material
when the animation ends and i can control the player ,the ball disappeared!
i take a screenshot and expect anyone can help me about the problem,thx
screenshot.PNG

That is the mesh for spectator pawn. Enable Hide Player in Matinee’s details panel and you wont see it.

thank you !the does worked!