VSTS extension - Failed to load

Hi,

I have created a sample VSTS extension for creating Hub by following the below link.

https://www.visualstudio.com/en-us/integrate/extensions/develop/add-hub

I could mange to publish and install the extension and the new Hub link is available in VSTS.

When I click on the hub link in VSTS , extension is not loaded and the page displays "Failed to load".

I am stuck now as I do not know how to debug the extensions. F12 tools doesn't help as the error occurred during loading extension.

Can any one please let me know how to debug the failing extensions in VSTS

Thanks,

Sreelatha