Error facing while installing on local. Guidance needed!

Hi ,
I followed the procedure as given and when I try to run the application, widget gets created but map doesn't appears.
"Maps key. Please create a new key for the application as soon as possible and prior to deployment by visiting, and provide your key to Cesium by setting the Cesium.BingMapsApi.defaultKey property before constructing the CesiumWidget or any other object that uses the Bing Maps API."

The I generated new key and replaced it at 'BingMapsApi.defaultKey', then also it didn't worked. Also i tried by replacing the key where default key was hardcoded.

Still getting same error.

OS used: Mac & Win 7
Browser: Firefox and Chrome

Kindly suggest some solution.