Fatal Error: Class 'MONGO' Not Found


I uploaded mongodb to my webserver to install mongodb. I cannot continue to install from the url directory at … /mongopress/mp-admin/install.php

From to the website url of my webserver at /mongopress/mp-admin/install.php the following error message is:

Fatal error: Class ‘MONGO’ not found in /home/mywebservername/mongopress/mp-includes/cache.php on line 86


The cache.php file is not in the /mongopress/mp-includes/cache.php

Should this be added or is it generated by mongopress?