Ok, so I installed google checkout per the instructions given in the documentation. I thought this would be pretty straight forward, but when I then tried to go to the admin section after uploading the site back to the server, I get this message:

Warning: main(includes/auto_loaders/config.core.php): failed to open stream: No such file or directory in /home/content/m/c/c/mccalld/html/ZC_install2125/admin/includes/initsystem.php on line 21

Warning: main(includes/auto_loaders/config.core.php): failed to open stream: No such file or directory in /home/content/m/c/c/mccalld/html/ZC_install2125/admin/includes/initsystem.php on line 21

Warning: main(): Failed opening 'includes/auto_loaders/config.core.php' for inclusion (include_path='.:/usr/local/lib/php') in /home/content/m/c/c/mccalld/html/ZC_install2125/admin/includes/initsystem.php on line 21

Warning: dir(includes/auto_loaders): failed to open dir: No such file or directory in /home/content/m/c/c/mccalld/html/ZC_install2125/admin/includes/initsystem.php on line 22

Fatal error: Call to undefined function: zen_get_languages() in /home/content/m/c/c/mccalld/html/ZC_install2125/admin/index.php on line 25

What does all this mean, and how the heck do I fix it?

Thanks!!