Warning: Use of undefined constant ON - assumed 'ON' (this will throw an Error in a future version of PHP) in C:\wamp\www\mantisbt\plugins\Source\pages\checkin.php on line 16

Fatal error: Uncaught Error: Call to undefined function plugin_config_get() in C:\wamp\www\mantisbt\plugins\Source\pages\checkin.php:16 Stack trace: #0 {main} thrown in C:\wamp\www\mantisbt\plugins\Source\pages\checkin.php on line 16