client_id undefined is invalid

client:127.0.0.1:51383 gateway:127.0.0.1:7272  client_id:7f00000108fc00000003 session:{"room_id":"1"
,"client_name":"yy"} onMessage:{"type":"pong"}
client:127.0.0.1:51383 gateway:127.0.0.1:7272  client_id:7f00000108fc00000003 session:{"room_id":"1"
,"client_name":"yy"} onMessage:{"type":"say","to_client_id":"undefined","to_client_name":"","content
":"5"}
client_id:7f00000108fc00000003  client_ip:2130706433
exception 'Exception' with message 'client_id undefined is invalid' in D:\wamp\www\zbj\chat\GatewayW
orker\Lib\Context.php:102
Stack trace:
#0 D:\wamp\www\zbj\chat\GatewayWorker\Lib\Gateway.php(452): GatewayWorker\Lib\Context::clientIdToAdd
ress('undefined')
#1 D:\wamp\www\zbj\chat\GatewayWorker\Lib\Gateway.php(78): GatewayWorker\Lib\Gateway::sendCmdAndMess
ageToClient('undefined', 5, '{"type":"say","...')
#2 D:\wamp\www\zbj\chat\Applications\Chat\Event.php(116): GatewayWorker\Lib\Gateway::sendToClient('u
ndefined', '{"type":"say","...')
#3 D:\wamp\www\zbj\chat\GatewayWorker\BusinessWorker.php(216): Event::onMessage('7f00000108fc000...'
, '{"type":"say","...')
#4 : GatewayWorker\BusinessWorker->onGatewayMessage(Object(Workerman\Connection\A
syncTcpConnection), Array)
#5 D:\wamp\www\zbj\chat\Workerman\Connection\TcpConnection.php(471): call_user_func(Array, Object(Wo
rkerman\Connection\AsyncTcpConnection), Array)
#6 : Workerman\Connection\TcpConnection->baseRead(Resource id #23)
#7 D:\wamp\www\zbj\chat\Workerman\Events\Select.php(253): call_user_func_array(Array, Array)
#8 D:\wamp\www\zbj\chat\Workerman\Worker.php(734): Workerman\Events\Select->loop()
#9 D:\wamp\www\zbj\chat\GatewayWorker\BusinessWorker.php(96): Workerman\Worker->run()
#10 D:\wamp\www\zbj\chat\Workerman\Worker.php(422): GatewayWorker\BusinessWorker->run()
#11 D:\wamp\www\zbj\chat\Workerman\Worker.php(339): Workerman\Worker::runAllWorkers()
#12 D:\wamp\www\zbj\chat\Applications\Chat\start_businessworker.php(36): Workerman\Worker::runAll()
#13 {main}