In trying to debug #12337 I added a sleep at the end of AppInitMain() to simulate being able to close the application late in the AppInitMain() process. If I close the splash screen at this point, I get a reliable crash when the splashs screen is deleted as it tries to disconnect itself from the wallet ShowProgress signal after Shutdown() has been called and the wallet has been deleted.
if (PaymentServer::ipcSendCommandLine())
        exit(EXIT_SUCCESS);
    
    
    app.createPaymentServer();
#endif
    
    
    app.installEventFilter(new GUIUtil::ToolTipToRichTextFilter(TOOLTIP_WRAP_THRESHOLD, &app));
#if QT_VERSION < 0x050000
    
    qInstallMsgHandler(DebugMessageHandler);
#else
#if defined(Q_OS_WIN)
    
    qApp->installNativeEventFilter(new WinShutdownMonitor());
#endif
    
    qInstallMessageHandler(DebugMessageHandler);
#endif
    
    app.parameterSetup();
    
    app.createOptionsModel(gArgs.IsArgSet("-resetguisettings"));
    
    uiInterface.InitMessage.connect(InitMessage);
    if (gArgs.GetBoolArg("-splash", DEFAULT_SPLASHSCREEN) && !gArgs.GetBoolArg("-min", false))
        app.createSplashScreen(networkStyle.data());
    int rv = EXIT_SUCCESS;