There appears to be an issue with the Facebook app for Windows Phone, with a number of readers reporting the same problem over on our forums. Should you install the Facebook app from the Marketplace and attempt to login you will be greeted by; "Sorry, there was an error." The app generally experiences problems when alterations are made on Facebook's end. A community moderator at Microsoft Answers has been made aware of the issue, but let's hope the team addresses this soon. In the mean time, the Facebook integration still works flawlessly.
Are you having these issues? Head on over to our forum to join the discussion.