Can't access dashboard index – error code

I have a client who moved from one host to another (I wasn’t involved initially), and I’m getting a strange error. If I try to access the wp-admin dashboard, I get this error:

Warning: require_once(/home/content/33/10669333/html/wp-admin/wp-includes/load.php) [function.require-once]: failed to open stream: No such file or directory in /home/content/33/10669333/html/wp-admin/wp-load.php on line 48

Fatal error: require_once() [function.require]: Failed opening required ‘/home/content/33/10669333/html/wp-admin/wp-includes/load.php’ (include_path=’.:/usr/local/php5_3/lib/php’) in /home/content/33/10669333/html/wp-admin/wp-load.php on line 48

Here’s the strange thing – this error shows if I go to
http://www.mysitehere.com/wp-admin

But if I go to a more internal link, something like
http://www.mysitehere.com/wp-admin/plugins.php
then I can access the dashboard just fine. And the site itself at http://www.mysitehere.com appears to be functioning properly.

Any ideas what might be causing the issue with the index page to the dashboard? Could it be a PHP error/misconfiguration on the new host? really just looking for some tips on how to go about troubleshooting this one. TIA!