04-13-2016 03:24 PM - edited 04-13-2016 03:44 PM
You shouldn't be getting this reference error. When modifing a tag template, you'll want to make sure you're referencing the 'b' object inside of the u.send function. This function will have access to the 'b' object and as such, you'll be able to reference your cookie. In addition, make sure you're referencing the exact value of the cookie name as seen in the utag.data object. Some of the utag_main cookies have two underscores in them such as "cp.utag_main__sn".
If you're still having issues, it would be helpful if you can include the code you're trying so we can help to diagnose it.