[Lynne]

You have some file or plugin somewhere that is looking for the files which you no longer have. You say you reuploaded the vb folder, but are you using your old vb database? If so, it's got your old plugins installed. Disable your plugins and see if you can log in:
Note: To temporarily disable the plugin system, edit config.php and add this line right under <?php

PHP Code:

define('DISABLE_HOOKS', true);