diff --git a/lib/modules/CoreParticipants.class.php b/lib/modules/CoreParticipants.class.php
index a9fac5c2a4206f6090eeef3a366e3186f6fd7c63..ef1fd0972541e2d9c6dd58f92ed194f6eb9f1272 100644
--- a/lib/modules/CoreParticipants.class.php
+++ b/lib/modules/CoreParticipants.class.php
@@ -16,6 +16,10 @@ class CoreParticipants extends CorePlugin implements StudipModule
      */
     public function getIconNavigation($course_id, $last_visit, $user_id)
     {
+        if ($user_id === 'nobody') {
+            return null;
+        }
+
         $auto_insert_perm = Config::get()->AUTO_INSERT_SEM_PARTICIPANTS_VIEW_PERM;
         // show the participants-icon only if the course is not an auto-insert-sem
         if (
@@ -122,6 +126,10 @@ class CoreParticipants extends CorePlugin implements StudipModule
      */
     public function getTabNavigation($course_id)
     {
+        if ($GLOBALS['user']->id === 'nobody') {
+            return [];
+        }
+
         $navigation = new Navigation(_('Teilnehmende'));
         $navigation->setImage(Icon::create('persons', Icon::ROLE_INFO_ALT));
         $navigation->setActiveImage(Icon::create('persons', Icon::ROLE_INFO));
diff --git a/lib/modules/GradebookModule.class.php b/lib/modules/GradebookModule.class.php
index ac8d69b2a4a26b9538fad2057f8cecfe9e99fa0a..531c0cdf95c2be5650b2e6271a4ea9b55d27b69c 100644
--- a/lib/modules/GradebookModule.class.php
+++ b/lib/modules/GradebookModule.class.php
@@ -45,6 +45,10 @@ class GradebookModule extends CorePlugin implements SystemPlugin, StudipModule
      */
     public function getIconNavigation($courseId, $lastVisit, $userId)
     {
+        if ($userId === 'nobody') {
+            return null;
+        }
+
         $title = _('Gradebook');
         if ($GLOBALS['perm']->have_studip_perm('tutor', $courseId, $userId)) {
             $changed = Instance::countBySQL(
diff --git a/lib/modules/LtiToolModule.class.php b/lib/modules/LtiToolModule.class.php
index 0383f115f640807a749030571daadbdd0c0404da..a36ea1500ded5ceaf5d221d7377aa52ac9e88ae5 100644
--- a/lib/modules/LtiToolModule.class.php
+++ b/lib/modules/LtiToolModule.class.php
@@ -37,6 +37,10 @@ class LtiToolModule extends CorePlugin implements StudipModule, SystemPlugin, Pr
      */
     public function getIconNavigation($course_id, $last_visit, $user_id)
     {
+        if ($user_id === 'nobody') {
+            return null;
+        }
+
         $title = CourseConfig::get($course_id)->LTI_TOOL_TITLE;
         $changed = LtiData::countBySQL('course_id = ? AND chdate > ?', [$course_id, $last_visit]);