Live search function suddenly stopped working!

Live search function suddenly stopped working!

  2. $.extend($.expr[":"], {
  3. "containsNC": function(elem, i, match, array) {
  4. return (elem.textContent || elem.innerText || "").toLowerCase().indexOf((match[3] || "").toLowerCase()) >= 0;
  5. }
  6. });
  7. $("input[name$='search']").keyup(function() {
  8. var filter = $(this).val();
  10. $("#contentchampions a:not(:containsNC(" + filter + "))").css("display","none");
  11. $("#contentchampions a:containsNC(" + filter + ")").css("display","block");
  12. });

This code has always been working. I didn't change anything and suddenly it stopped working. I tried to remove all of the Jquery around it, and even change the Jquery version (as this was  the only thing I changed)

I get the following error:  Uncaught TypeError: Cannot read property '3' of undefined

Please help me, since I have no idea what is going on.
You can check the full code on  http://mitcheljager.com/demo/mobatierlist/ (Please use Chrome) use CTRL Shift + I and fill in something on the Search bar to see the error.