diff --git a/app/controllers/calendar/schedule.php b/app/controllers/calendar/schedule.php
index 52c6f36c9e8bc113bb42e4432fe39087be3327a7..6fb51c401e254c61e3ca8a7136352ee8f2e04650 100644
--- a/app/controllers/calendar/schedule.php
+++ b/app/controllers/calendar/schedule.php
@@ -243,7 +243,11 @@ class Calendar_ScheduleController extends AuthenticatedController
                 $this->render_template('calendar/schedule/_entry_course');
             } else if ($id) {
                 $entry_columns = CalendarScheduleModel::getScheduleEntries($GLOBALS['user']->id, 0, 0, $id);
-                $entries = array_pop($entry_columns)->getEntries();
+                $entries = [];
+                $entry_columns = array_pop($entry_columns);
+                if ($entry_columns) {
+                    $entries = $entry_columns->getEntries();
+                }
                 $this->show_entry = array_pop($entries);
                 $this->render_template('calendar/schedule/_entry_schedule');
             }