Thread:Extension talk:Maps/Map editor does exist but no maps preview

Hi every one, In my Wiki, I downloaded maps and validator extensions then added the extracted files to extension directory in mediawiki then I pasted these lines in the local setting.php file in the same way after this line"# Add more configuration options below."

# Validator require_once( "$IP/extensions/Validator/Validator.php" ); # Maps require_once( "$IP/extensions/Maps/Maps.php" ); ?>

I have map editor in the special pages but with no maps preview What did I do wrongly,I wish to know?