Atto style dropdown button not working if table button is not present

Go to Site administration ► Plugins ► Text editors ► Atto HTML editor ► Atto toolbar settings On the "Toolbar config" text area, make sure that its contents are the same as the Default. If not, copy the default values and paste into the "Toolbar config" text area and click on "Save changes" Go to a page with an Atto editor. (i.e. Edit profile page, by going to Preferences ► User account ► Edit profile) On the Atto editor, play with the buttons. Confirm that: All buttons function as expected. There should be no errors displayed in the JavaScript console. Go back to to Site administration ► Plugins ► Text editors ► Atto HTML editor ► Atto toolbar settings On the "Toolbar config" text area, remove the "table" entry which can be found on the "insert" line. Click "Save changes" Go to a page with an Atto editor. (i.e. Edit profile page, by going to Preferences ► User account ► Edit profile) On the Atto editor, play with the buttons. Confirm that: All buttons function as expected. There should be no errors displayed in the JavaScript console.