1.This is your first time using Zen Cart™ and you haven't yet completed the normal Installation procedure.
If this is the case for you, you will need to upload the "zc_install" folder using your FTP program, and then run zc_install/index.php via your browser (or reload this page to see a link to it).
2.Your /includes/configure.php and/or /admin/includes/configure.php file contains invalid path information and/or invalid database-connection information.
If you recently edited your configure.php files for any reason, or maybe moved your site to a different folder or different server, then you'll need to review and update all your settings to the correct values for your server.
See the Online FAQ and Tutorials area on the Zen Cart™ website for assistance.
3.Additional Details: includes/configure.php file contents invalid. ie: DIR_FS_CATALOG not valid or not set