I've written 30 articles. All but one of them is marked as visible to 'signed-in users'. I just changed one manually to 'everyone' but I want to do that for all of them in one go.
I go to 'manage articles', I select them all. The 'article settings' button appears, I click it, I select change permissions in the pop up menu, I get a pop up window with the option 'permission type'. When I select 'visible to' as an option, I get an error