JQuery unrecognized expression on Ajax response

Question

I have this JQuery Ajax Form.

$(\'#modal-body-sign-in\').on(\'submit\', \'#sign-in\', function(e) {
        e.preventDefault();
        var data = $(this).se         


        

Answer 1

If you are using jQuery1.9, the problem may lie in the content being loaded. There is a new update which requires that the first character in the response be a < [AKA the less than symbol]. Even whitespace will cause this to break and throw the dreaded "Uncaught Error: Syntax error, unrecognized expression:" error.

I'd recommend checking this before using the suggested workaround above. Its not a bug its a security effort.

http://jquery.com/upgrade-guide/1.9/#jquery-htmlstring-versus-jquery-selectorstring