E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: de.eleven.viergewinnt, PID: 18605
                  android.view.WindowManager$BadTokenException: Unable to add window -- token android.os.BinderProxy@52770c7 is not valid; is your activity running?
                      at android.view.ViewRootImpl.setView(ViewRootImpl.java:903)
                      at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:372)
                      at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:105)
                      at android.app.Dialog.show(Dialog.java:408)
                      at android.support.v7.app.AlertDialog$Builder.show(AlertDialog.java:958)
                      at de.eleven.viergewinnt.OnlineGameActivity.showCloseDialog(OnlineGameActivity.java:832)
                      at de.eleven.viergewinnt.OnlineGameActivity$17.run(OnlineGameActivity.java:533)
                      at android.os.Handler.handleCallback(Handler.java:751)
                      at android.os.Handler.dispatchMessage(Handler.java:95)
                      at android.os.Looper.loop(Looper.java:154)
                      at android.app.ActivityThread.main(ActivityThread.java:6776)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410)