diff --git a/src/main/webapp/app/overview/course-faq/course-faq.component.html b/src/main/webapp/app/overview/course-faq/course-faq.component.html
index 57e8599419e6..67cc28d2f00f 100644
--- a/src/main/webapp/app/overview/course-faq/course-faq.component.html
+++ b/src/main/webapp/app/overview/course-faq/course-faq.component.html
@@ -27,7 +27,7 @@
         </div>
     </div>
     <hr class="" />
-    @if (faqs.length === 0) {
+    @if (faqs?.length === 0) {
         <h2 class="markdown-preview" jhiTranslate="artemisApp.faq.noExisting"></h2>
     }
     <div>
@@ -35,7 +35,7 @@ <h2 class="markdown-preview" jhiTranslate="artemisApp.faq.noExisting"></h2>
             <jhi-course-faq-accordion [faq]="faq"></jhi-course-faq-accordion>
         }
     </div>
-    @if (filteredFaqs.length === 0 && faqs.length > 0) {
+    @if (filteredFaqs?.length === 0 && faqs.length > 0) {
         <h2 class="markdown-preview" jhiTranslate="artemisApp.faq.noMatching"></h2>
     }
 </div>
diff --git a/src/main/webapp/app/overview/course-overview.component.html b/src/main/webapp/app/overview/course-overview.component.html
index 29aca3568574..e0b62084f8b6 100644
--- a/src/main/webapp/app/overview/course-overview.component.html
+++ b/src/main/webapp/app/overview/course-overview.component.html
@@ -255,7 +255,7 @@
         routerLinkActive="active"
         [jhiFeatureToggleHide]="sidebarItem.featureToggle"
         [title]="sidebarItem.title"
-        (click)="itemsDrop.close()"
+        (click)="itemsDrop?.close()"
     >
         <ng-template *ngTemplateOutlet="iconTextTemplate; context: { $implicit: sidebarItem }" />
     </a>
@@ -274,7 +274,7 @@
         routerLinkActive="active"
         [jhiFeatureToggleHide]="sidebarItem.featureToggle"
         [title]="sidebarItem.title"
-        (click)="itemsDrop.close()"
+        (click)="itemsDrop?.close()"
     >
         <ng-template *ngTemplateOutlet="iconTextTemplate; context: { $implicit: sidebarItem }" />
     </a>
diff --git a/src/main/webapp/app/shared/sidebar/sidebar.component.html b/src/main/webapp/app/shared/sidebar/sidebar.component.html
index ea806fa17e2a..d972ad363a29 100644
--- a/src/main/webapp/app/shared/sidebar/sidebar.component.html
+++ b/src/main/webapp/app/shared/sidebar/sidebar.component.html
@@ -25,7 +25,7 @@
                                 </button>
 
                                 <div ngbDropdownMenu>
-                                    @if (sidebarData.messagingEnabled) {
+                                    @if (sidebarData?.messagingEnabled) {
                                         <button (click)="createDirectChat()" class="p-2" ngbDropdownItem>
                                             <fa-icon [icon]="faUser" class="item-icon" [fixedWidth]="true"></fa-icon>
                                             <span jhiTranslate="artemisApp.courseOverview.sidebar.createDirectChat"></span>