Observers do not include file from the right location

The observers property includefile is not relative to dirroot anymore.

Add the following observer to any events file (for instance lib/db/events.php):

$observers = array(

      array(

        'eventname' => '\core\event\group_created',

        'callback' => 'print_object',

        'includefile' => '/lib/datalib.php'

      )

)

Purge cache, and create a new group, and make sure the content of the event has been printed out.