อันนี้ตรง LOG นะค่ะที่มันแจ้ง ว่าผิด
   .facebook$2$1.onCompleted(facebook.java:61)
            at com.facebook.Request$1.onCompleted(Request.java:283)
            at com.facebook.Request$4.run(Request.java:1668)
            at android.os.Handler.handleCallback(Handler.java:733)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5001)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
            at dalvik.system.NativeStart.main(Native Method)