When creating/editing views through the UI (at the path /admin/structure/views/view/view_name), the 'Add' buttons for various options (Fields, Contextual Filters, Relationships, etc) silently fail. No ajax errors appear in the browser console and nothing appears in the report logs.
This bug appears to raise its head randomly when deleting a contextual filter or relationship and then saving the view. When it does happen, clicking any 'add' button results in the ajax spinwheel but no option windows pop-up. Refreshing the page / leaving the page and coming back do not fix it, the only solution I've found so far is to actually delete the entire view and start over.
