I made the windows update procedure again. After the Windows update Poser was very slow again in the material editor. I figured out wich update it is now it's KB5000802 (Betriebssystembuilds 19041.867 und 19042.867) you must uninstall.

But I am afraid I can't use Poser 11 for long time anymore. And I realy would not buy poser 12. I don't trust Poser anymore. What if Poser 13 comes out. They will let all the users of Poser 12 standing in the rain again like they do it with poser 11 users. I don't need that again

I'm happy that I can use DAZ Studio and Blender the longer the better.