I am trying to authenticate user using OAuth and retrieve the user data. When the user is not signed into twitter the authentication works and I am able to get the user details. But if the user is already signed in on twitter I am getting this error message ‘403 Forbidden: The server understood the request, but is refusing to fulfill it.’ . In some posts they said to make all the requests through https instead of http. That I have done. I have downloaded the code for authentication from ‘http://net.tutsplus.com/tutorials/php/how-to-authenticate-users-with-twitter-oauth/’ .Please help.