Facebook SDK not running on iPhone Simulator, only on device

I have a strange issue trying to run the Facebook iOS SDK Dem开发者_JAVA技巧oApp (from facebook website).

On the device the app is working perfectly, but on the simulator a grey screen appears after login and permission requests. It doesn't even load fbDidLogin() function.

Anybody else having this problem?

Fixed. In my case, I was using the same APP_ID in several XCode projects. I deleted the apps in iPhone Simulator, rebuilt the Facebook Demo App and worked. I think it was confusing for which project to log in or something.