Crash : IllegalStateException

[AndroidDeveloperLB]

Got this exception while pressing the middle button twice in a row:

12-23 20:53:17.510 4883-4883/? E/AndroidRuntime: FATAL EXCEPTION: main Process: uk.co.nickbutcher.adaptiveiconplayground, PID: 4883 java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first. at android.view.ViewGroup.addViewInner(ViewGroup.java:4937) at android.view.ViewGroup.addView(ViewGroup.java:4768) at android.view.ViewGroup.addView(ViewGroup.java:4708) at android.support.v7.widget.RecyclerView$5.addView(RecyclerView.java:751) at android.support.v7.widget.ChildHelper.addView(ChildHelper.java:107) at android.support.v7.widget.RecyclerView$LayoutManager.addViewInt(RecyclerView.java:7995) at android.support.v7.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:7953) at android.support.v7.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:7941) at android.support.v7.widget.GridLayoutManager.layoutChunk(GridLayoutManager.java:579) at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1498) at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:591) at android.support.v7.widget.GridLayoutManager.onLayoutChildren(GridLayoutManager.java:170) at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3691) at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:3408) at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:3960) at android.view.View.layout(View.java:19659) at android.view.ViewGroup.layout(ViewGroup.java:6075) at android.support.design.widget.CoordinatorLayout.layoutChild(CoordinatorLayout.java:1166) at android.support.design.widget.CoordinatorLayout.onLayoutChild(CoordinatorLayout.java:851) at android.support.design.widget.CoordinatorLayout.onLayout(CoordinatorLayout.java:870) at android.view.View.layout(View.java:19659) at android.view.ViewGroup.layout(ViewGroup.java:6075) at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323) at android.widget.FrameLayout.onLayout(FrameLayout.java:261) at android.view.View.layout(View.java:19659) at android.view.ViewGroup.layout(ViewGroup.java:6075) 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:19659) at android.view.ViewGroup.layout(ViewGroup.java:6075) at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323) at android.widget.FrameLayout.onLayout(FrameLayout.java:261) at android.view.View.layout(View.java:19659) at android.view.ViewGroup.layout(ViewGroup.java:6075) 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:19659) at android.view.ViewGroup.layout(ViewGroup.java:6075) 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:761) at android.view.View.layout(View.java:19659) at android.view.ViewGroup.layout(ViewGroup.java:6075) at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2496) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2212) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1392) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6752) at android.view.Choreographer$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$FrameDisplayEventReceiver.run(Choreographer.java:897) at android.os.Handler.handleCallback(Handler.java:790) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:164) 12-23 20:53:17.510 4883-4883/? E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:6494) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)