Exception occurred when client connection disconnected

[tmkasun]

[W 170319 17:19:53 KnnectHandler:54] Lost client at host 112.135.84.94 [E 170319 17:19:53 concurrent:129] Future exception was never retrieved: Traceback (most recent call last): File "/usr/local/lib/python2.7/dist-packages/tornado/gen.py", line 285, in wrapper yielded = next(result) File "/home/ubuntu/web/knnect/server_core/repo/KnnectHandler.py", line 71, in notify_clients yield [client.write_message(message) for client in self.ws_handler.connections] File "/usr/local/lib/python2.7/dist-packages/tornado/websocket.py", line 212, in write_message message = tornado.escape.json_encode(message) File "/usr/local/lib/python2.7/dist-packages/tornado/escape.py", line 82, in json_encode return json.dumps(value).replace("</", "<\\/") File "/usr/lib/python2.7/json/__init__.py", line 244, in dumps return _default_encoder.encode(obj) File "/usr/lib/python2.7/json/encoder.py", line 207, in encode chunks = self.iterencode(o, _one_shot=True) File "/usr/lib/python2.7/json/encoder.py", line 270, in iterencode return _iterencode(o, 0) File "/usr/lib/python2.7/json/encoder.py", line 184, in default raise TypeError(repr(o) + " is not JSON serializable") TypeError: ObjectId('58ce705db4170b418cb3670d') is not JSON serializable [I 170319 17:19:53 KnnectHandler:79] Update LK_Status with id = {'updatedExisting': True, u'nModified': 1, u'ok': 1.0, u'n': 1}