I ran into this very unpleasant problem all day, and through Google I found many people with the same problem with no answers related to the new Facebook API for Android. I have completed the following steps listed here:
https://developers.facebook.com/docs/getting-started/facebook-sdk-for-android/3.0/
When I run the sample application on my device, I get the following: 
When I run it on the emulator, it works. I understand that this is due to the introduction of SSO on Facebook. The emulator does not have facebook installed, so it subscribes for the first time, but the device starts the facebook application and for some reason gives this error, and when I go back, it looks like I did not log into facebook at all and there is no active session (although I know that when it launches the facebook application, I can browse friends, etc.)
I cannot delete facebook on my device, and even if I could, it would be unacceptable to users of applications. If possible, I would like to keep the SSO function, but somehow make it work!
I spent all day moving back and forth using my hash keys and generated them through my device code + and using keytool, and they match, so the problem is not related to this. In addition, the sample application runs on the emulator, which certainly means its SSO problem. Thanks in advance.
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