diff --git a/apps/account/serializers/user.py b/apps/account/serializers/user.py
index 1c0a605..90d07ce 100644
--- a/apps/account/serializers/user.py
+++ b/apps/account/serializers/user.py
@@ -26,6 +26,10 @@ class UserProfileSerializer(serializers.ModelSerializer):
         read_only_fields = ['email', 'info', 'skill', 'device_id', 'slug', 'saved_location']
     
     def get_saved_location(self, obj):
+        # Check if user is authenticated and has location_history attribute
+        if not obj.is_authenticated or not hasattr(obj, 'location_history'):
+            return None
+            
         last_location = obj.location_history.order_by('-at_time').first()
         if last_location:
             return {
diff --git a/apps/course/views/course.py b/apps/course/views/course.py
index 59c57b7..ece8362 100644
--- a/apps/course/views/course.py
+++ b/apps/course/views/course.py
@@ -454,6 +454,22 @@ class CourseOnlineClassTokenValidateAPIView(GenericAPIView):
         print(f"[Online Validate GET] user={request.user}")
         print(f"[Online Validate GET] user.is_authenticated={request.user.is_authenticated}")
         print(f"[Online Validate GET] user.id={request.user.id if request.user.is_authenticated else 'N/A'}")
+        print(f"[Online Validate GET] Authorization Header={request.META.get('HTTP_AUTHORIZATION', 'NOT FOUND')}")
+        print(f"[Online Validate GET] All Headers={dict((k, v) for k, v in request.META.items() if k.startswith('HTTP_'))}")
+        
+        # Debug: Check if token exists in database
+        auth_header = request.META.get('HTTP_AUTHORIZATION', '')
+        if auth_header.startswith('Token '):
+            token_key = auth_header.split(' ')[1]
+            try:
+                from rest_framework.authtoken.models import Token
+                token_obj = Token.objects.get(key=token_key)
+                print(f"[Online Validate GET] Token found in DB - user={token_obj.user} user_id={token_obj.user.id}")
+            except Token.DoesNotExist:
+                print(f"[Online Validate GET] Token NOT found in DB - token={token_key[:10]}...")
+            except Exception as e:
+                print(f"[Online Validate GET] Token check error - {str(e)}")
+        
         print("=" * 80)
         
         logger.info(f"[Online Validate GET] Request received - slug={slug} user_id={request.user.id if request.user.is_authenticated else 'anonymous'}")