I deactivated messaging due to the mail with the potential security risk.
I have now upgraded my platforms and wanted to enable it again, but the option has been removed from siteadministration -> advanced features, and the settings has been removed from siteadministration -> modules -> messages.
When i look in the files (moodle/admin/settings/subsystems.php) i see that the option to enable messaging is missing from the files.
The messaging settings is still reachable with https://DOMAIN/admin/message.php but not available from the siteadministration menu.
I added the 5 missing lines in moodle/admin/settings/subsystems.php from my backup:
$optionalsubsystems->add(new admin_setting_configcheckbox('messaging', new lang_string('messaging', 'admin'), new lang_string('configmessaging','admin'), 1));
new lang_string('messagingallusers', 'admin'),
new lang_string('configmessagingallusers', 'admin'),
And cleared all cache, but still no luck....
Any idea how i can enable messaging again after upgrading to 3.7?