Thanks for your help guys, but no changes have been made at all to the files since no files were moved. I only changed the host records.
The URL's in the config file don't have the 'www' in the front.
Cache has already been cleared.
So all of the proposed solutions have already been applied and it's still not working. I've changed IP back to what it was before and now I'm getting the “Apache is working on your cPanel and WHM Server” message instead of the error message from before.
Do I need to change something in the database somewhere? Please propose other solutions.
Given that you are getting a smarty error, your DNS is resolving properly and you are getting to the index.php (or admin) of the site. Apache will not use smarty so you are “in the cart” and are getting some kind of error where the internals of the cart are trying to throw an exception.
Easy check is to place:
die("Got here: ".__FILE__);
as the first code line of index.php
My bet is your cache is not really cleared. Remove the whole var/cache directory manually by just changing the name of var/cache to var/cache.backup.
Look through init.php at the order of initialization. Insert the same die statement between the calls to the initialization routines until you no longer see the 'die' statement but instead see the smarty error. The init routine above your die is most likely the area where you are failing. It can be a slow, manual process if you don't have real PHP debugging tools at your disposal.