Liquid error: Solution::ArticleMeta#visible? delegated to solution_folder_meta.visible?, but solution_folder_meta is nil: #<Solution::ArticleMeta id: 33000111408, position: nil, art_type: 1, thumbs_up: 0, thumbs_down: 0, hits: 0, solution_folder_meta_id: 33000219057, account_id: 704202, created_at: "2017-08-10 12:46:31", updated_at: nil, available: nil, draft_present: nil, published: nil, outdated: nil>