diff --git a/client/src/pages/cockpit/attendanceCheckPage/AttendanceCheckPage.vue b/client/src/pages/cockpit/attendanceCheckPage/AttendanceCheckPage.vue
index d6ad6461..7433a216 100644
--- a/client/src/pages/cockpit/attendanceCheckPage/AttendanceCheckPage.vue
+++ b/client/src/pages/cockpit/attendanceCheckPage/AttendanceCheckPage.vue
@@ -88,23 +88,25 @@ const onSubmit = async () => {
 const loadAttendanceData = async () => {
   resetState();
   // with changing variables `useQuery` does not seem to work correctly
-  const res = await graphqlClient.query(
-    ATTENDANCE_CHECK_QUERY,
-    {
-      courseSessionId: state.attendanceCourseSelected.id.toString(),
-    },
-    {
-      requestPolicy: "network-only",
+  if (state.attendanceCourseSelected) {
+    const res = await graphqlClient.query(
+      ATTENDANCE_CHECK_QUERY,
+      {
+        courseSessionId: state.attendanceCourseSelected.id.toString(),
+      },
+      {
+        requestPolicy: "network-only",
+      }
+    );
+    const attendanceUserList =
+      res.data?.course_session_attendance_course?.attendance_user_list ?? [];
+    for (const user of attendanceUserList) {
+      if (!user) continue;
+      state.userPresence.set(user.user_id, user.status === "PRESENT");
+    }
+    if (attendanceUserList.length !== 0) {
+      state.attendanceSaved = true;
     }
-  );
-  const attendanceUserList =
-    res.data?.course_session_attendance_course?.attendance_user_list ?? [];
-  for (const user of attendanceUserList) {
-    if (!user) continue;
-    state.userPresence.set(user.user_id, user.status === "PRESENT");
-  }
-  if (attendanceUserList.length !== 0) {
-    state.attendanceSaved = true;
   }
 };
 
@@ -122,7 +124,8 @@ watch(
   () => {
     log.debug("attendanceCourseSelected changed", state.attendanceCourseSelected);
     loadAttendanceData();
-  }
+  },
+  { immediate: true }
 );
 </script>
 
diff --git a/server/vbv_lernwelt/course/serializer_helpers.py b/server/vbv_lernwelt/course/serializer_helpers.py
index cfeba369..f0cf9116 100644
--- a/server/vbv_lernwelt/course/serializer_helpers.py
+++ b/server/vbv_lernwelt/course/serializer_helpers.py
@@ -9,6 +9,7 @@ from vbv_lernwelt.core.utils import StringIDField
 
 class CourseBaseSerializer(ItWagtailBaseSerializer):
     id = StringIDField()
+    content_assignment_id = StringIDField()
     course = SerializerMethodField()
     course_category = SerializerMethodField()
     circles = SerializerMethodField()