diff --git a/lib.php b/lib.php
index 9bf761260794f76244ce238a9f3e884aff6ae5d1..4b0ea6e002522dc345fc2310b9f8f70b6aec9352 100644
--- a/lib.php
+++ b/lib.php
@@ -43,13 +43,13 @@ function local_hsh_boostnavigation_extend_navigation(global_navigation $navigati
             $string = $coursename;
 
             $newCourse = navigation_node::create($string, new moodle_url('/course/view.php', array('id' => $course->id)), global_navigation::TYPE_COURSE, null, $string, new pix_icon('i/course', 'grades'));
-	        $newCourse->add_class('m-l-3');
+            $newCourse->add_class('m-l-3');
             $newCourse->showinflatnavigation = true;
             $semester->add_node($newCourse);
         }
     }
 
-    if(!empty($semesterList)) {
+    if(!empty($semesterList) && isset($semesterList)) {
         array_shift($semesterList);
         array_shift($semesterKeys);
         // Semesterlise sortieren, so dass "no-semester" unten ist
@@ -59,7 +59,11 @@ function local_hsh_boostnavigation_extend_navigation(global_navigation $navigati
         // Semesterliste sortieren (Neuestes Semeste oben)
         if($semesterOrder == 0) { // Wenn die Order auf 1 ist -> Neueste Unten
             rsort($semesterList);
-            $newestNode = $semesterList[0];
+            if(isset($semesterList[0])) {
+                $newestNode = $semesterList[0];
+            } else {
+                $newestNode = $unabhaengig;
+            }
         }
 
         // Position der Semesterunabhängigen Kurse - Oberhalb der Semester
@@ -72,14 +76,19 @@ function local_hsh_boostnavigation_extend_navigation(global_navigation $navigati
         // Gewünsche Anzhal anzuzeigender Semester aus dem Array lesen und innerhalb der Navigation darstellen
         if($semesterOrder == 0) {
             // Neueste Oben
-            $newestNode = $semesterList[0]->key;
-            for ($i = 0; $i < $maxSemesters; $i++) {
-                if($i < sizeof($semesterList) && $semesterList[$i]) {
-                    $customnav->add_node($semesterList[$i]);
-                } else {
-                    break;
+            if(isset($semesterList[0])) {
+                $newestNode = $semesterList[0]->key;
+                for ($i = 0; $i < $maxSemesters; $i++) {
+                    if($i < sizeof($semesterList) && $semesterList[$i]) {
+                        $customnav->add_node($semesterList[$i]);
+                    } else {
+                        break;
+                    }
                 }
+            } else {
+                $newestNode = $unabhaengig;
             }
+
         } else {
             // Neueste Unten
             $count = sizeof($semesterList) - $maxSemesters;
@@ -109,7 +118,7 @@ function local_hsh_boostnavigation_extend_navigation(global_navigation $navigati
         // JavaScript-Code genommen und angepasst von local/boostnavigation/amd/src
         $PAGE->requires->js_call_amd('local_hsh_boostnavigation/collapse', 'init', [$collapsenodesforjs]);
 
-         foreach ($collapsenodesforjs as $node) {
+        foreach ($collapsenodesforjs as $node) {
             user_preference_allow_ajax_update('local_hsh_boostnavigation-collapse_'.$node.'_node', PARAM_BOOL);
         }
     }
diff --git a/version.php b/version.php
index 9441da6fa0894edf46eddcacea7d3dd0d307d14f..fea4156c40c9825c9838ead2f77d11a8e6d566f2 100644
--- a/version.php
+++ b/version.php
@@ -25,11 +25,11 @@
 defined('MOODLE_INTERNAL') || die();
 
 $plugin->component = 'local_hsh_boostnavigation';
-$plugin->version = 2018072500;
-$plugin->release = 'v1.1-r3';
+$plugin->version = 2018082900;
+$plugin->release = 'v1.1-r4';
 
 $plugin->requires = 2016120500;
 #$plugin->maturity = MATURITY_STABLE;
 $plugin->dependencies = array('theme_boost' => 2016120500,
-        'block_course_overview_campus' => 2017033100,
-        'local_boostnavigation' => 2017100901);
+    'block_course_overview_campus' => 2017033100,
+    'local_boostnavigation' => 2017100901);