Does the error only show on vBAdvanced pages? If so, then it's caused by vBAdvanced's hacked method of creating a front page and it's nothing I can help with I'm afraid
I'm also unable to help with how to get it to display on vBAdvanced because I don't run vBAdvanced on any of our sites, so you'll have to ask on their support forums to get it to work properly.
Fillip