I have updated a copy of my site from J2.5 to J3.4 on localhost, carefully checking, updating and/or replacing all components, modules, and plugins as needed, and the updated site works fine on localhost. I then use Akeeba to take a backup of the localhost site, copied it up to the live site server and restored it. Now I get error 500 - JHtmlBehavior: :mootools not supported. when I try to access the live site front end, and a white screen when I try to access the back end. How do I proceed from here?