diff --git a/app/controllers/calendar/schedule.php b/app/controllers/calendar/schedule.php
index c20fbea88c8a12bf7bd695642d9c994647faf7e4..ae6d2cb98aadb7787324df5de8bbfc8fafa0d666 100644
--- a/app/controllers/calendar/schedule.php
+++ b/app/controllers/calendar/schedule.php
@@ -245,7 +245,11 @@ 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');
             }