Normal Close button is not shown in modal dialog when window title is not set.
Example: http://zkfiddle.org/sample/26rh2l3/12-Close-button-is-not-shown-in-modal-dialog or
Example code
@Command("ok") public void ok() { Window window = (Window)Executions.createComponents("inner.zul", null, null); window.setBorder(true); window.setClosable(true); window.setTitle("Title"); window.doModal(); } @Command("wrong") public void wrong() { Window window = (Window)Executions.createComponents("inner.zul", null, null); window.setBorder(true); window.setClosable(true); window.doModal(); }