diff --git a/app/controllers/admin/courseplanning.php b/app/controllers/admin/courseplanning.php
index 44b372db7a3f811f58d7f05cc39f4ffac7a0dbf1..be4113386687c650d0052145a2ca76f4d430d65f 100644
--- a/app/controllers/admin/courseplanning.php
+++ b/app/controllers/admin/courseplanning.php
@@ -12,10 +12,12 @@ class Admin_CourseplanningController extends AuthenticatedController
     {
         parent::before_filter($action, $args);
 
-        if ($GLOBALS['perm']->have_perm('admin')) {
-            Navigation::activateItem('/browse/my_courses/schedule');
+        if (!$GLOBALS['perm']->have_perm('admin')) {
+            throw new AccessDeniedException();
         }
 
+        Navigation::activateItem('/browse/my_courses/schedule');
+
         $this->insts = Institute::getMyInstitutes($GLOBALS['user']->id);
 
         if (empty($this->insts) && !$GLOBALS['perm']->have_perm('root')) {
diff --git a/lib/classes/InstituteCalendarHelper.php b/lib/classes/InstituteCalendarHelper.php
index 95e9e8d5ad679a02da52b547596debb099ea7447..343bc765b0eacd726a33237394bde6002cfcb012 100644
--- a/lib/classes/InstituteCalendarHelper.php
+++ b/lib/classes/InstituteCalendarHelper.php
@@ -142,7 +142,7 @@ class InstituteCalendarHelper
         $df = DatafieldEntryModel::findByModel($course, self::COLUMN_DATAFIELD_ID);
         if ($df[0]) {
             $event_columns = self::getCourseEventcolumns($course);
-            if (!is_array($event_columns[$event_id])) {
+            if (isset($event_columns[$event_id]) && !is_array($event_columns[$event_id])) {
                 unset($event_columns[$event_id]);
             }
             $event_columns[$event_id][$institut_id] = $column;