You need to specify
ToolDialog(0, #(Editor), closeButton?:)
It defaults to false because most of our dialogs have other buttons like OK/Cancel in which case it is unclear whether the ‘X’ close button acts like OK or like Cancel.
Dialog now ignores style: and exStyle: because we found it caused too much inconsistency in our applications because people would specify different options. And only certain combinations of style and exStyle work properly.