webpack.optimize.OccurrenceOrderPlugin

Dear all ,

I get a TypeError: Cannot read property 'call' of undefined.
when i try to add the webpack OccurrenceOrderPlugin to the app-npm-webpack example.
Can any one tall me this is a issue or my mistake ?

the console error output

vendor.f5ed478….js:1 Uncaught TypeError: Cannot read property 'call' of undefinedr @ vendor.f5ed478….js:1(anonymous function) @ app.f5ed478….js:1r @ vendor.f5ed478….js:1window.webpackJsonp @ vendor.f5ed478….js:1(anonymous function) @ app.f5ed478….js:1

and the code

return e[t].call(u.exports,u,u.exports,r),u.loaded=!0,u.exports}