Open a course Click 'Backup' Click on the Cancel button Confirm that the dialogue is centred Confirm that the dialogue is modal and has a lightbox Edit lib/ajax/getsiteadminbranch.php echo some content out after ajax_capture_output(); Refresh any page Expand the Site administration Confirm that an error was displayed centred, and modal Change your echo to: throw new moodle_exception('banana'); Refresh any page Expand the Site administration Confirm that an error was displayed centred, and modal Open your JS console and enter: Y.use('moodle-core-notification'); Confirm that each of the following displays a dialogue immediately, centred, and modal (with lightbox ajaxException: foo = new M.core.ajaxException({}); alert foo.destroy(); foo = new M.core.alert({}); confirm foo.destroy(); foo = new M.core.confirm({}); exception foo.destroy(); foo = new M.core.exception({}); Confirm that the following does not display a new dialogue foo.destroy(); foo = new M.core.dialogue({}); Now open it and confirm that it is: centred not modal (has no lightbox) foo.show();