unexpected error following a crash

[aslancarlos]

This happened now and it's not the first time, I guess is the 7th time that is happened.

How could I help to solve this bug?

^[[32m[2012-12-11 10:04:27.848] [INFO] message - ^[[39mfrom _lMjK7HSzP8cTkMb3be8: {"type":"COLLABROOM","component":"pad","data":{"type":"USER_CHANGES","baseRev":3200,"changeset":"Z:4uu>0|5=57*0=1f$","apool":{"numToAttrib":{"0":["strikethrough","true"]},"nextNum":1}}}
^[[31m[2012-12-11 10:04:27.853] [ERROR] console - ^[[39mTypeError: Cannot read property 'json' of undefined
at exports.updatePadClients (/var/www/etherpad/src/node/handler/PadMessageHandler.js:682:46)
at _asyncMap (/var/www/etherpad/src/node_modules/async/lib/async.js:190:13)
at async.forEach (/var/www/etherpad/src/node_modules/async/lib/async.js:94:25)
at _asyncMap (/var/www/etherpad/src/node_modules/async/lib/async.js:187:17)
at async.parallel.results (/var/www/etherpad/src/node_modules/async/lib/async.js:459:34)
at Object.exports.updatePadClients.async.forEach.async.whilst.async.parallel.socketio.sockets.sockets.(anonymous function).json.send.type as callback
at /var/www/etherpad/src/node_modules/ueberDB/CloneAndAtomicLayer.js:120:17
at exports.database.getSub (/var/www/etherpad/src/node_modules/ueberDB/CacheAndBufferLayer.js:345:7)
at exports.database.get (/var/www/etherpad/src/node_modules/ueberDB/CacheAndBufferLayer.js:142:5)
at exports.database.getSub (/var/www/etherpad/src/node_modules/ueberDB/CacheAndBufferLayer.js:317:8)
^[[32m[2012-12-11 10:04:27.853] [INFO] console - ^[[39mgraceful shutdown...
^[[31m[2012-12-11 10:04:27.853] [ERROR] console - ^[[39mTypeError: Cannot read property 'json' of undefined
at exports.updatePadClients (/var/www/etherpad/src/node/handler/PadMessageHandler.js:682:46)
at _asyncMap (/var/www/etherpad/src/node_modules/async/lib/async.js:190:13)
at async.forEach (/var/www/etherpad/src/node_modules/async/lib/async.js:94:25)
at _asyncMap (/var/www/etherpad/src/node_modules/async/lib/async.js:187:17)
at async.parallel.results (/var/www/etherpad/src/node_modules/async/lib/async.js:459:34)
at Object.exports.updatePadClients.async.forEach.async.whilst.async.parallel.socketio.sockets.sockets.(anonymous function).json.send.type as callback
at /var/www/etherpad/src/node_modules/ueberDB/CloneAndAtomicLayer.js:120:17
at exports.database.getSub (/var/www/etherpad/src/node_modules/ueberDB/CacheAndBufferLayer.js:345:7)
at exports.database.get (/var/www/etherpad/src/node_modules/ueberDB/CacheAndBufferLayer.js:142:5)
at exports.database.getSub (/var/www/etherpad/src/node_modules/ueberDB/CacheAndBufferLayer.js:317:8)