Login Failed: invalid_key when Android Facebook app is installed

As Sean suggests in his second tack...

I fixed the issue by removing this line (which uses SSO):

    mFacebook.authorize(activity, mAppId, PERMS_NEEDED, new LoginDialogListener(r));

in favor of this line (which does not):

    mFacebook.authorize(
            activity, 
            PERMS_NEEDED,
            Facebook.FORCE_DIALOG_AUTH,   // avoids SSO
            new LoginDialogListener(r));

refer from:

https://github.com/facebook/facebook-android-sdk/issues/191