531494 Facebook APP Troubleshooting

We are looking for someone with experience of Facebook Apps and the Facebook API to get us over a snag. My developers are building the functionality into my website, to post from the website, straight onto my twitter account and Facebook page. Twitter is working fine but we are getting an error "OAuthException: Error validating application." when trying to post to Facebook. I need someone to either edit the code we have {Attached} if they can see a simple fix, or create the app for us and pass admin rights over to me. Please let me know which route you feel would be best when bidding.