TypeError: undefined is not a function

[yanmingsohu]

in 'lib/logger.js':43:: Logger.emit('error', err)
but 'Logger.emit' is undefined

TypeError: undefined is not a function
at WriteStream. (E:\Nodejs_Projects\source-manager-prj\node_modul
es\sinopia\lib\logger.js:43:16)
at WriteStream.emit (events.js:107:17)
at onwriteError (_stream_writable.js:317:10)
at onwrite (_stream_writable.js:335:5)
at WritableState.onwrite (_stream_writable.js:105:5)
at fs.js:1800:14
at FSReqWrap.strWrapper (fs.js:570:5)