When I finished to animate a scene (let a part rotate), I discovered a strange
artifact in the scene: something like a tall but thin black line or cut-out
where no cut-out is supposed to be.
Please see the video file here (closer to the end of the video):
https://www.facebook.com/video.php?v=1032986830049905&set=vb.100000157941289&type=3
