Keep getting "Bad request" messages in browser after adding JS

Question

I have added this script in my Drupal 7 site to make the site remember the last clicked Quicktab and then open that tab on page reload:

// JavaScript Document
(function($) {

    Drupal.behaviors.quicktabsTabMemory = {
      attach: function(context, settings) {
        // The .each() is in case there is more than one quicktab on a page.
        $('.quicktabs-wrapper', context).each(function () {

          var $this = $(this);
          var wrapperID = $this.attr('id');

                var nid = settings.nordtec_klister['currentNid']; // getting the nid on the client side

          var $activeTabLink = $('.quicktabs-tabs li.active a', context);
          var activeTabLinkID = $activeTabLink.attr('id');

          // Use a unique cookie namespace for each set of Quicktabs, which
          // should allow for more than one set on a page.
          var cookieName = 'Drupal-quicktabs-active-tab-id-' + wrapperID + 'nid='+ nid;
          // Default cookie options.
          var cookieOptions = {path: '/'};

          // Click the tab ID if a cookie exists otherwise set a cookie for
          // the default active tab.
          var $cookieValue = $.cookie(cookieName);
          if ($cookieValue) {
            $('#' + $cookieValue).click();
          }
          else {
            $.cookie(cookieName, activeTabLinkID, cookieOptions);
          }

          // Set the click handler for all tabs, this updates the cookie on every
          // tab click.
          $this.find('ul.quicktabs-tabs a').click(function quicktabsCookieClickHandler() {
            $activeTabLink = $this.find('.quicktabs-tabs li.active a', context);
            activeTabLinkID = $activeTabLink.attr('id');
            $.cookie(cookieName, activeTabLinkID, cookieOptions);
          });
        });
      }
    };

})(jQuery);

This works as a charm, BUT ever since I added this I keep getting this message in the browser (Chrome)...

Bad Request Your browser sent a request that this server could not understand. Size of a request header field exceeds server limit.

...after maybe 1 or 2 working days of browsing the site, adding and editing content (many tabs open with different pages etc). I can only assume that it's not a coincidence that those error messages began to show soon after I added this script.

So my question is: What should I do in order to avoid those messages? Clear out all cookies after a certain time? I have tried to limit the cookie life time to 28800 seconds and also the garbage collector life time to that same value in settings.php:

ini_set('session.gc_maxlifetime', 28800);
ini_set('session.cookie_lifetime', 28800);

This helped some, the messages does not occur as often after this, but they do still happen once a week or so.

Answer 1

Finally found the solution to my problem, in case anyone else makes the same mistake.

The problem with my cookie is this line from the code above:

var cookieName = 'Drupal-quicktabs-active-tab-id-' + wrapperID + 'nid='+ nid;

Cookie names cannot contain equal characters (or spaces, commas, semi-colons etc). That will create errors. So i simply changed "=" to "-" in my code line above, and the errors went away.