wrong session_data bug

main.py

@@ -897,7 +897,7 @@ def get_user_level(session):
     :return:
     """
     ulevel = 0
-    if session[USER_DATA_SESSION_NAME] is not None:
+    if session.get(USER_DATA_SESSION_NAME, None) is not None:
         ulevel = 2
     ulevel = max(ulevel, DEFAULT_ANONYMOUS_USER_LEVEL)