Olá, após fazer a sincronização com o servidor minha aplicação dá erre erro:
E/UncaughtException: java.lang.NullPointerException: Attempt to invoke virtual method 'int android.graphics.Bitmap.getWidth()' on a null object reference
                         at android.graphics.Bitmap.createScaledBitmap(Bitmap.java:702)
                         at br.com.example.admin.agenda.adapter.AlunosAdapter.getView(AlunosAdapter.java:78)
                         at android.widget.AbsListView.obtainView(AbsListView.java:2372)
                         at android.widget.ListView.makeAndAddView(ListView.java:2052)
                         at android.widget.ListView.fillDown(ListView.java:786)
                         at android.widget.ListView.fillFromTop(ListView.java:847)
                         at android.widget.ListView.layoutChildren(ListView.java:1826)
                         at android.widget.AbsListView.onLayout(AbsListView.java:2171)
                         at android.view.View.layout(View.java:19590)
                         at android.view.ViewGroup.layout(ViewGroup.java:6053)
                         at android.support.v4.widget.SwipeRefreshLayout.onLayout(SwipeRefreshLayout.java:610)
                         at android.view.View.layout(View.java:19590)
                         at android.view.ViewGroup.layout(ViewGroup.java:6053)
                         at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1080)
                         at android.view.View.layout(View.java:19590)
                         at android.view.ViewGroup.layout(ViewGroup.java:6053)
                         at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
                         at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
                         at android.view.View.layout(View.java:19590)
                         at android.view.ViewGroup.layout(ViewGroup.java:6053)
                         at android.support.v7.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:443)
                         at android.view.View.layout(View.java:19590)
                         at android.view.ViewGroup.layout(ViewGroup.java:6053)
                         at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
                         at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
                         at android.view.View.layout(View.java:19590)
                         at android.view.ViewGroup.layout(ViewGroup.java:6053)
                         at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1791)
                         at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1635)
                         at android.widget.LinearLayout.onLayout(LinearLayout.java:1544)
                         at android.view.View.layout(View.java:19590)
                         at android.view.ViewGroup.layout(ViewGroup.java:6053)
                         at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
                         at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
                         at com.android.internal.policy.DecorView.onLayout(DecorView.java:758)
                         at android.view.View.layout(View.java:19590)
                         at android.view.ViewGroup.layout(ViewGroup.java:6053)
                         at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2484)
                         at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2200)
                         at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1386)
                         at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6733)
                         at android.view.Choreographer$CallbackRecord.run(Choreographer.java:911)
                         at android.view.Choreographer.doCallbacks(Choreographer.java:723)
                         at android.view.Choreographer.doFrame(Choreographer.java:658)
                         at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:897)
                         at android.os.Handler.handleCallback(Handler.java:789)
                         at android.os.Handler.dispatchMessage(Handler.java:98)
                         at android.os.Looper.loop(Looper.java:164)
                         at android.app.ActivityThread.main(ActivityThread.java:6541)
                         at java.lang.reflect.Method.invoke(Native Method)
                         at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
                         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767) 
            