diff --git a/lms/djangoapps/course_home_api/outline/tests/test_view.py b/lms/djangoapps/course_home_api/outline/tests/test_view.py
index 12d57aa35bce..4f40d9a80192 100644
--- a/lms/djangoapps/course_home_api/outline/tests/test_view.py
+++ b/lms/djangoapps/course_home_api/outline/tests/test_view.py
@@ -715,7 +715,7 @@ def test_empty_blocks_complete(self):
         """
         self.add_blocks_to_course()
         CourseEnrollment.enroll(self.user, self.course.id)
-        url = reverse('course-home:course-sidebar-blocks', args=[self.course.id])
+        url = reverse('course-home:course-navigation', args=[self.course.id])
         response = self.client.get(url)
         assert response.status_code == 200
 
@@ -731,7 +731,7 @@ def test_blocks_complete_with_problem(self, problem_complete):
         CourseEnrollment.enroll(self.user, self.course.id)
         self.create_completion(problem, int(problem_complete))
 
-        response = self.client.get(reverse('course-home:course-sidebar-blocks', args=[self.course.id]))
+        response = self.client.get(reverse('course-home:course-navigation', args=[self.course.id]))
 
         sequence_data = response.data['blocks'][str(self.sequential.location)]
         vertical_data = response.data['blocks'][str(self.vertical.location)]
@@ -750,7 +750,7 @@ def test_blocks_completion_stat(self):
         CourseEnrollment.enroll(self.user, self.course.id)
         self.create_completion(completed_problem, 1)
         self.create_completion(uncompleted_problem, 0)
-        response = self.client.get(reverse('course-home:course-sidebar-blocks', args=[self.course.id]))
+        response = self.client.get(reverse('course-home:course-navigation', args=[self.course.id]))
 
         expected_sequence_completion_stat = {
             'completion': 0,
@@ -779,7 +779,7 @@ def test_blocks_completion_stat_all_problem_completed(self):
         CourseEnrollment.enroll(self.user, self.course.id)
         self.create_completion(problem1, 1)
         self.create_completion(problem2, 1)
-        response = self.client.get(reverse('course-home:course-sidebar-blocks', args=[self.course.id]))
+        response = self.client.get(reverse('course-home:course-navigation', args=[self.course.id]))
 
         expected_sequence_completion_stat = {
             'completion': 1,
diff --git a/lms/djangoapps/course_home_api/outline/views.py b/lms/djangoapps/course_home_api/outline/views.py
index f1d60ffda003..21b982088c6b 100644
--- a/lms/djangoapps/course_home_api/outline/views.py
+++ b/lms/djangoapps/course_home_api/outline/views.py
@@ -513,8 +513,11 @@ def mark_complete_recursive(self, block):
         """
         Mark blocks as complete or not complete based on the completions_dict.
         """
+        if not block:
+            return block
+
         if 'children' in block:
-            block['children'] = [self.mark_complete_recursive(child) for child in block['children']]
+            block['children'] = [self.mark_complete_recursive(child) for child in block['children'] if child]
             completable_children = self.get_completable_children(block)
             block['complete'] = all(child['complete'] for child in completable_children)
             block['completion_stat'] = self.get_block_completion_stat(block, completable_children)