500 Server Error When Activating Classifieds

I briefly had an older version of Classifieds installed, but uninstalled it a short time later after deciding I wasn't ready to take on that project at the time.

Went to install the newest version today, and it brings down the site with a 500 Sever Error.

Error logs are showing this:

PHP Fatal error: Class 'CustomPress_Core' not found in /opt/bitnami/apps/wordpress/htdocs/wp-content/plugins/classifieds/core/custompress/core/content-types.php on line 18

Any ideas or suggestions for a fix would be appreciated....