Thread:Extension talk:ConfirmUsersEmail/Another Error

After installing the extension, I got the following error:

Fatal error: Call to a member function addMessages on a non-object in blabla.com/extensions/ConfirmUsersEmail/ConfirmUsersEmail.php on line 42

This is the function in which addMessages appears:

function efConfirmUsersEmail global $wgMessageCache; require_once( dirname( __FILE__ ) . '/ConfirmUsersEmail.i18n.php' ); foreach( efConfirmUsersEmailMessages as $lang => $messages ) $wgMessageCache->addMessages( $messages, $lang ); }

Does anybody have suggestions how I could fix this?

Thanks in advance

Hermann