diff --git a/maro/communication/message.py b/maro/communication/message.py
index 59752692..6ae4cdc8 100644
--- a/maro/communication/message.py
+++ b/maro/communication/message.py
@@ -2,19 +2,12 @@
 # Licensed under the MIT license.
 
 # native lib
-import sys
 import uuid
 from enum import Enum
 from typing import Union
 
-# private lib
-from maro.utils import InternalLogger
-from maro.utils.exit_code import NON_RESTART_EXIT_CODE
-
 from .utils import session_id_generator
 
-logger = InternalLogger(component_name="message")
-
 
 class SessionType(Enum):
     """Communication session categories.
@@ -113,5 +106,4 @@ class SessionMessage(Message):
         elif self.session_type == SessionType.NOTIFICATION:
             self.session_stage = session_stage if session_stage else NotificationSessionStage.REQUEST
         else:
-            logger.error(f"Receive unrecognized session type {self.session_type}, please use the SessionType class.")
-            sys.exit(NON_RESTART_EXIT_CODE)
+            raise KeyError(f'Unsupported session type {self.session_type}.')