Thanks for reply, my problem is different, the artifact appear on printing too, my macpro don't slow down. The video now is public, give me a feedback, thanks.
Mario, now I can see your video. I have already seen that bug from another person. Clipping to a group can also massively slow down PS in this current release or, like in your case, cause artifacts.
Stefan, do you have a file that exhibits the behavior in the video or the slowdown you're referencing? If so, that would be helpful for me to track down the issue and get it fixed.
Senior Product Manager - Customer Advocacy - Digital Imaging