Unable to create New Topic

[Guiri]

Click the New Topic button in a category does nothing. Not sure how I did this. This error shows up in my output.log:

Missing error handler on `socket`.
TypeError: Cannot call method 'emit' of undefined
    at /home/ubuntu/Node/src/socket.io/rooms.js:52:35
    at /home/ubuntu/Node/node_modules/async/lib/async.js:246:17
    at /home/ubuntu/Node/node_modules/async/lib/async.js:122:13
    at _each (/home/ubuntu/Node/node_modules/async/lib/async.js:46:13)
    at async.each (/home/ubuntu/Node/node_modules/async/lib/async.js:121:9)
    at _asyncMap (/home/ubuntu/Node/node_modules/async/lib/async.js:245:13)
    at Object.map (/home/ubuntu/Node/node_modules/async/lib/async.js:216:23)
    at Object.rooms.broadcast (/home/ubuntu/Node/src/socket.io/rooms.js:42:8)
    at SocketModules.chats.sync (/home/ubuntu/Node/src/socket.io/modules.js:105:8)
    at callMethod (/home/ubuntu/Node/src/socket.io/index.js:204:2)

[julian]

Is the plugin composer-default activated?