Codeigniter无法连接到服务器--Google同步失败

I am modifying this code in a controller for synchronization with google calendar. The following is the original that gives no errors and synchronizes fine:

        // :: ADD GCAL EVENTS THAT ARE NOT PRESENT ON E!A
        $google_calendar = $provider['settings']['google_calendar'];
        $events = $this->google_sync->get_sync_events($google_calendar, $start, $end);

        foreach($events->getItems() as $event) {
            $results = $this->appointments_model->get_batch(array('id_google_calendar' => $event->getId()));
            if (count($results) == 0) {
                // Record doesn't exist in E!A, so add the event now.

                $appointment = array(

                    'start_datetime' => date('Y-m-d H:i:s', strtotime($event->start->getDateTime())),
                    'end_datetime' => date('Y-m-d H:i:s', strtotime($event->end->getDateTime())),
                    'is_unavailable' => TRUE,
                    'notes' => $event->getSummary() . ' ' .$event->getDescription(),
                    'id_users_provider' => $provider_id,
                    'id_google_calendar' => $event->getId(),
                    'id_users_customer' => NULL,
                    'id_services' => NULL,
                );

                $this->appointments_model->add($appointment);
            }
        }

The following is the code with my modifications. It produces a server connection error.

        // :: ADD GCAL EVENTS THAT ARE NOT PRESENT ON E!A
        $google_calendar = $provider['settings']['google_calendar'];
        $events = $this->google_sync->get_sync_events($google_calendar, $start, $end);

        foreach($events->getItems() as $event) {
            $results = $this->appointments_model->get_batch(array('id_google_calendar' => $event->getId()));
            if (count($results) == 0) {
                // Record doesn't exist in E!A, so add the event now.

             $str = $event->getDescription()
             $expnote = explode('|',$str)

                $appointment = array(

                    'start_datetime' => date('Y-m-d H:i:s', strtotime($event->start->getDateTime())),
                    'end_datetime' => date('Y-m-d H:i:s', strtotime($event->end->getDateTime())),
                    'is_unavailable' => TRUE,
                    'notes' => $event->getSummary() . ' ' . $expnote[0],
                    'id_users_provider' => $provider_id,
                    'id_google_calendar' => $event->getId(),
                    'id_users_customer' => $expnote[2],
                    'id_services' => $expnote[1],
                );

                $this->appointments_model->add($appointment);
            }
        } 

What is wrong with my code?