I\'m trying to deploy a contextual gadget in my domain. I have followed the development guides but the gadget does not show up. I think that the problem is about \"Data acce
The root of the issue here lies in the fact that the Developer Guidelines for the contextual gadget are outdated. Google deprecated that way of authentication in the admin panel in November 2013 but did not update the contextual gadget page.
Creating a new project and following these steps fixed the "Grant Data" problem that you are experiencing.