erizoController.js crashed

hi all
when i publish 9 streams,and subscribed each
other,the erizoController.js crashed, log as follow:

/usr/yunzis/licode/erizo_controller/erizoController/roomController.js:233
var index =
erizos[publishers[publisher_id]].publishers.indexOf(pu
^
TypeError: Cannot read property ‘publishers’ of undefined
at Object.that.removePublisher
(/usr/yunzis/licode/erizo_controller/erizoController/roomController.js:233:57)
at Socket.
(/usr/yunzis/licode/erizo_controller/erizoController/erizoController.js:735:60)
at Socket.emit [as $emit] (events.js:95:17)
at Socket.onDisconnect
(/usr/yunzis/licode/node_modules/socket.io/lib/socket.js:153:10)
at SocketNamespace.handleDisconnect
(/usr/yunzis/licode/node_modules/socket.io/lib/namespace.js:229:46)
at Manager.onClientDisconnect
(/usr/yunzis/licode/node_modules/socket.io/lib/manager.js:501:29)
at WebSocket.Transport.end
(/usr/yunzis/licode/node_modules/socket.io/lib/transport.js:467:20)
at Parser.
(/usr/yunzis/licode/node_modules/socket.io/lib/transports/websocket/hybi-16.js:52:10)
at Parser.emit (events.js:92:17)
at Parser.opcodeHandlers.8
(/usr/yunzis/licode/node_modules/socket.io/lib/transports/websocket/hybi-16.js:382:12)
2015-04-02 16:34:12.773 - INFO: CloudHandler - ErizoController 1 in
222.174.255.34 does not respond. Deleting it.
2015-04-02 16:34:12.774 - INFO: CloudHandler - [CLOUD HANDLER]: Warning!
No erizoController is available.

why? how to fix?