No solution solved my problem. You can go at your Dashboard to Elementor->Tools-> version Control. Here you can simple roll back your Plugins to 2.8.4 and everything works.
After 6 Days the Support got no Solution. It’s a shame!
Ok, theres the choice of the parent products now. When I click on the attribute button and do a choice, theres a blank screen. The adress is
/wp-admin/edit.php?post_type=product&page=woocommerce_molds
Nothing happend in Version 4.2.2
