In Moodle 2.3, the code issues the following message:

• The module presenter does not define the standard capability mod/presenter:addinstance

The following code (or something similar) should be added to db/access.php:

'mod/forumng:addinstance' => array(
'riskbitmask' => RISK_XSS,

'captype' => 'write',
'contextlevel' => CONTEXT_COURSE,
'archetypes' => array(
'editingteacher' => CAP_ALLOW,
'manager' => CAP_ALLOW
),
'clonepermissionsfrom' => 'moodle/course:manageactivities'
),