Okapi Installation Issue

I've downloaded the Okapi folder and added all of the files to my site, but whenever I try to access the site, it gives me this error message:

Warning: The magic method __isset() must have public visibility and cannot be static in .../application/libraries/Zend/Config.php on line 184
Your Omeka database configuration file has not been set up properly. Please edit the configuration and reload this page.

I'm fairly new to this, so any help would be appreciated.

The Okapi package was developed for earlier versions of Omeka by designers and developers outside of the Omeka team. There isn't a new version, and so the earlier package probably won't work with version 2.0. It's also something that we don't support.

If you are upgrading an older site that is running Okapi you might want to consider another theme.