diff --git a/seahub/adfs_auth/backends.py b/seahub/adfs_auth/backends.py
index 4eb5df597a..47d99ab76f 100644
--- a/seahub/adfs_auth/backends.py
+++ b/seahub/adfs_auth/backends.py
@@ -50,7 +50,6 @@ class Saml2Backend(ModelBackend):
 
     def authenticate(self, session_info=None, attribute_mapping=None, create_unknown_user=True, org_id=None, **kwargs):
         if session_info is None or attribute_mapping is None:
-            logger.error('Session info or attribute mapping are None')
             return None
 
         name_id = session_info.get('name_id', '')
diff --git a/seahub/adfs_auth/views.py b/seahub/adfs_auth/views.py
index 5a4b273b62..d63b076550 100644
--- a/seahub/adfs_auth/views.py
+++ b/seahub/adfs_auth/views.py
@@ -276,6 +276,10 @@ def assertion_consumer_service(request, org_id=None, attribute_mapping=None, cre
     oq_cache.delete(session_id)
     session_info = response.session_info()
     attribute_mapping = attribute_mapping or SAML_ATTRIBUTE_MAPPING
+    if not attribute_mapping:
+        logger.error('ADFS attribute mapping is not valid.')
+        return render_error(request, login_failed_error_msg)
+
 
     # saml2 connect
     relay_state = request.POST.get('RelayState', '/saml/complete/')
@@ -314,6 +318,7 @@ def assertion_consumer_service(request, org_id=None, attribute_mapping=None, cre
         return HttpResponseRedirect(relay_state)
 
     if not session_info:
+        logger.error('ADFS session info is not valid.')
         return render_error(request, login_failed_error_msg)
 
     name_id = session_info.get('name_id', '')
diff --git a/seahub/seadoc/apis.py b/seahub/seadoc/apis.py
index d59822f793..327f6d6bf4 100644
--- a/seahub/seadoc/apis.py
+++ b/seahub/seadoc/apis.py
@@ -414,6 +414,9 @@ def latest_entry(request, file_uuid, filename):
             filepath = os.path.join(parent_path, filename)
             filepath = os.path.normpath(filepath)
             file_obj = seafile_api.get_dirent_by_path(repo_id, filepath)
+            if not file_obj:
+                logger.warning(f'file {filepath} not found')
+                return None
             dt = datetime.fromtimestamp(file_obj.mtime)
             return dt
         except Exception as e: