I got troubling with following error when signing in Google. It make me crazy and waste of my time. I uploaded difficultly using command line to Google App Engine. I fainted as soon as I found the solution for that error. Of course, every problem is easy if you know the solution.

400 Bad request error

The solution is have to adjust your computer time with country time zone. 🙂 haaha Why don’t error message show to do that?

Reference : 400 Bad Request during oAuth handshake from Eclipse plug-in