YUI crashes on pages where files in block "Site Main Menu" are set to be opened in popup.
YUI generates code as in example below that crashes page which stops YUI working on drag-drop, collapsable etc etc, block modify etc

Y.on('click', window.open('http://blabla.com/mod/resource/view.php?id=3965&redirect=1', '', 'width=800,height=600,toolbar=no,location=no,menubar=no,copyhistory=no,status=no,directories=no,scrollbars=yes,resizable=yes'); return false;, "#onclick5579971d2727639", null);

Ex.
1) Add file to Block "Site Main Menu"
2) Set file opening to "Popup"
3) Verify page crashes javascript with error and with code set at bottom of page