They are required by the system.
public function is_uninstall_allowed() {
global $DB;
+ if ($this->name === 'missing') {
+ // qbehaviour_missing is used by the system. It cannot be uninstalled.
+ return false;
+ }
+
return !$DB->record_exists('question_attempts', array('behaviour' => $this->name));
}
public function is_uninstall_allowed() {
global $DB;
+ if ($this->name === 'missingtype') {
+ // qtype_missingtype is used by the system. It cannot be uninstalled.
+ return false;
+ }
+
return !$DB->record_exists('question', array('qtype' => $this->name));
}