Web App Builder - (401) unauthorised

[AndrewTerwiel]

I've just started using Web App Builder and have been following the instructions to create a custom widget here: Create a custom in-panel widget—Web AppBuilder for ArcGIS (Developer Edition) | ArcGIS for Developer...

When I first attempted to test the widget via this URL: http://[your host name:3344]/webapp/?config=config-demo.json I got a Access-Control-Allow-Origin error. I then set this header on the server and made its value "*". I then attempted to test the widget again and received this error: "Unable to load http://<webserver>/arcgis/sharing/portals/self?f=json&dojo.preventCache=1425517676066 status: 401".

Is anyone able to help me resolve this please?

[RobertScheitlin__GISP]

Andrew,

   This issue has been addressed a few time. Here is one of the links:

stemapp/sample-configs folder? Does this exist?

[AndrewTerwiel]

I added a new setting to MIME Types in IIS. This has fixed the problem. The MIME Type extension is json and the MIME type is application/javascript.

A few hours later this stopped working again, so I have unmarked this as correct.