I just noticed that many warriors have put incorrect settings for the facebook profile ID. Most of warriors have added profile ID in CP. In that case, We get "The page you requested was not found." error. I think there is an issue with Vbulletin or something.
So I added #!/FB_user_Name in CP. Now it works
P.s: This may a very simple task, But I saw many invalid links in members profile for FB.