If you’re using jquery 2.0 or newer, it is no longer supported in internet explorer 8 or older. You can use the older jquery lib to make things work again with IE8 though.
Note that the following code has the current at time of posting versions of jquery, you should replace this with whichever version of 2.x you are using, and check if there is a newer ver for 1.9.x as well.
ALSO note- since IE8 will be using an older version of jquery, you’ll likely need to test this separately to make sure your site still works with the 1.9.x version. Big headache? Sure.
<!–[if (!IE)|(gt IE 8)]><!–>
<!–[if lte IE 8]>