Visibility Button under design/Widgets doesn't open

Hello

Since a couple of weeks the custom sidebars plugin doesn't work probably - maybe due to an update or because another plugin disturbs it? I tried to deactivate those I installed after custom sidebars, but no change. All plugins now activated are needed...

Design/Widgets
Visibility button doesn't work any longer. I can klick it, but nothing happens. Same goes for the clone button.

Please help my because I need to make some changes in visibility for some categories. Pages and posts are no problem - changes on the post oder page side work.

Thanks a lot for your fast help.

Best Regard
Michaela