Cannot install sidebars still only get to define where your sidebar should appear

I still can't find where I can reply to your post and add attachmrnts on https://premium.wpmudev.org/forums/topic/cannot-install-sidebars-still-only-get-to-define-where-your-sidebar-should-appear-1#post-711337

All my widgets can be replaced but when I select a sidebar location for new one Testing and say OK nothing changes.

I am going around incircles!

Peter