Error: Module build failed: TypeError: Cannot read property 'content' of undefined

Hi All,

I am using Ionic 2, and have just moved some pages from one project to another, now I get the error below at run-time.

If anyone can advise, I would appreciate it.

Error: Module build failed: TypeError: Cannot read property 'content' of undefined
    at Object.typescriptSourcemapLoaderMemory (E:\Development\IDE\ionic-apps\firebase-chat-master\node_modules\@ionic\app-scripts\dist\webpack\typescript-sourcemap-loader-memory.js:21:34)

More info:

Your system information:

 ordova CLI: 6.4.0
Ionic Framework Version: 2.0.0-rc.3
Ionic CLI Version: 2.1.18
Ionic App Lib Version: 2.1.9
Ionic App Scripts Version: 0.0.45
ios-deploy version: Not installed
ios-sim version: Not installed
OS: Windows 10
Node Version: v6.9.2
Xcode version: Not installed