401. That’s an error. Error: invalid_client
For one of my clients I have to build very simple website to host it in Azure. By the way Azure rocks! I love it and soon I will write at last a few post about it :). Anyway one of the requirement was that the site should have possibility to authenticate users, it shouldn’t be accessible to everyone. I’ve resided to use OAuth 2.0 provided by Google as it’s already pre configured for ASP.NET web sites. Process of configuration was very simple and very fast, without any errors but when I run my site I get message, Google API Error: invalid_client: 401. That’s an error. Error: invalid_client
Strange, as Google Client ID and Google Client secret was correct. After some digging in I’ve discovered that to use OAuth from Google you have to fill also information on Consent screen. It’s not obvious as as error page from Google doesn’t indicate that something is missing on your developer consoler. Instead you get information that something is wrong with Client ID
At last email address and Product Name must be filled. When you enter information at Consent screen and save your application will be able authenticate without any problem.