403 Forbidden error on authorization


In my android application I create an in-app browser in my application.
I redirect user to "https://api.twitter.com/oauth/authenticate?oauth_token=abcded1234"
So user goes to enter his username and password.
But after that user gets this error:
“403 Forbidden: The server understood the request, but is refusing to fulfill it”

What is the cause for that ?
Thank you