diff --git a/Modules/QtWidgets/include/QmitkMultiWidgetLayoutSelectionWidget.h b/Modules/QtWidgets/include/QmitkMultiWidgetLayoutSelectionWidget.h
index 63baf6b973..8dc74d2942 100644
--- a/Modules/QtWidgets/include/QmitkMultiWidgetLayoutSelectionWidget.h
+++ b/Modules/QtWidgets/include/QmitkMultiWidgetLayoutSelectionWidget.h
@@ -1,62 +1,65 @@
 /*============================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center (DKFZ)
 All rights reserved.
 
 Use of this source code is governed by a 3-clause BSD license that can be
 found in the LICENSE file.
 
 ============================================================================*/
 
 #ifndef QMITKMULTIWIDGETLAYOUTSELECTIONWIDGET_H
 #define QMITKMULTIWIDGETLAYOUTSELECTIONWIDGET_H
 
 #include "MitkQtWidgetsExports.h"
 
 #include "ui_QmitkMultiWidgetLayoutSelectionWidget.h"
 
 #include <nlohmann/json.hpp>
 
 // qt
 #include "QWidget"
 
 /**
 * @brief
 *
 *
 */
 class MITKQTWIDGETS_EXPORT QmitkMultiWidgetLayoutSelectionWidget : public QWidget
 {
   Q_OBJECT
 
 public:
 
   QmitkMultiWidgetLayoutSelectionWidget(QWidget* parent = nullptr);
 
 Q_SIGNALS:
 
   void LayoutSet(int row, int column);
+
+  // needs to be connected via Qt::DirectConnection (usually default), to ensure the stream pointers validity
   void SaveLayout(std::ostream* outStream);
+
   void LoadLayout(const nlohmann::json* jsonData);
 
 private Q_SLOTS:
 
   void OnTableItemSelectionChanged();
   void OnSetLayoutButtonClicked();
   void OnSaveLayoutButtonClicked();
   void OnLoadLayoutButtonClicked();
   void OnLayoutPresetSelected(int index);
 
 private:
 
   void Init();
 
 
   Ui::QmitkMultiWidgetLayoutSelectionWidget ui;
   std::map<int, nlohmann::json> m_PresetMap;
 
 };
 
 #endif // QMITKMULTIWIDGETLAYOUTSELECTIONWIDGET_H
diff --git a/Plugins/org.mitk.gui.qt.mxnmultiwidgeteditor/src/QmitkMxNMultiWidgetEditor.cpp b/Plugins/org.mitk.gui.qt.mxnmultiwidgeteditor/src/QmitkMxNMultiWidgetEditor.cpp
index ab9d0be839..ff93413c38 100644
--- a/Plugins/org.mitk.gui.qt.mxnmultiwidgeteditor/src/QmitkMxNMultiWidgetEditor.cpp
+++ b/Plugins/org.mitk.gui.qt.mxnmultiwidgeteditor/src/QmitkMxNMultiWidgetEditor.cpp
@@ -1,238 +1,238 @@
 /*============================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center (DKFZ)
 All rights reserved.
 
 Use of this source code is governed by a 3-clause BSD license that can be
 found in the LICENSE file.
 
 ============================================================================*/
 
 #include "QmitkMxNMultiWidgetEditor.h"
 
 #include <mitkCoreServices.h>
 #include <mitkIPreferencesService.h>
 #include <mitkIPreferences.h>
 
 #include <berryIWorkbenchPage.h>
 #include <berryIWorkbenchPartConstants.h>
 #include <berryUIException.h>
 
 // mxn multi widget editor plugin
 #include "QmitkMultiWidgetDecorationManager.h"
 
 // mitk qt widgets module
 #include <QmitkMxNMultiWidget.h>
 #include <QmitkInteractionSchemeToolBar.h>
 #include <QmitkMultiWidgetConfigurationToolBar.h>
 
 // qt
 #include <QHBoxLayout>
 
 const QString QmitkMxNMultiWidgetEditor::EDITOR_ID = "org.mitk.editors.mxnmultiwidget";
 
 struct QmitkMxNMultiWidgetEditor::Impl final
 {
   Impl();
   ~Impl() = default;
 
   QmitkInteractionSchemeToolBar* m_InteractionSchemeToolBar;
   QmitkMultiWidgetConfigurationToolBar* m_ConfigurationToolBar;
 };
 
 QmitkMxNMultiWidgetEditor::Impl::Impl()
   : m_InteractionSchemeToolBar(nullptr)
   , m_ConfigurationToolBar(nullptr)
 {
   // nothing here
 }
 
 //////////////////////////////////////////////////////////////////////////
 // QmitkMxNMultiWidgetEditor
 //////////////////////////////////////////////////////////////////////////
 QmitkMxNMultiWidgetEditor::QmitkMxNMultiWidgetEditor()
   : QmitkAbstractMultiWidgetEditor()
   , m_Impl(std::make_unique<Impl>())
 {
   // nothing here
 }
 
 QmitkMxNMultiWidgetEditor::~QmitkMxNMultiWidgetEditor()
 {
   GetSite()->GetPage()->RemovePartListener(this);
 }
 
 berry::IPartListener::Events::Types QmitkMxNMultiWidgetEditor::GetPartEventTypes() const
 {
   return Events::CLOSED | Events::OPENED | Events::HIDDEN | Events::VISIBLE;
 }
 
 void QmitkMxNMultiWidgetEditor::PartClosed(const berry::IWorkbenchPartReference::Pointer& partRef)
 {
   if (partRef->GetId() == QmitkMxNMultiWidgetEditor::EDITOR_ID)
   {
     const auto& multiWidget = dynamic_cast<QmitkMxNMultiWidget*>(GetMultiWidget());
     if (nullptr != multiWidget)
     {
       multiWidget->RemovePlanesFromDataStorage();
       multiWidget->ActivateMenuWidget(false);
     }
   }
 }
 
 void QmitkMxNMultiWidgetEditor::PartOpened(const berry::IWorkbenchPartReference::Pointer& partRef)
 {
   if (partRef->GetId() == QmitkMxNMultiWidgetEditor::EDITOR_ID)
   {
     const auto& multiWidget = dynamic_cast<QmitkMxNMultiWidget*>(GetMultiWidget());
     if (nullptr != multiWidget)
     {
       multiWidget->AddPlanesToDataStorage();
       multiWidget->ActivateMenuWidget(true);
     }
   }
 }
 
 void QmitkMxNMultiWidgetEditor::PartHidden(const berry::IWorkbenchPartReference::Pointer& partRef)
 {
   if (partRef->GetId() == QmitkMxNMultiWidgetEditor::EDITOR_ID)
   {
     const auto& multiWidget = dynamic_cast<QmitkMxNMultiWidget*>(GetMultiWidget());
     if (nullptr != multiWidget)
     {
       multiWidget->ActivateMenuWidget(false);
     }
   }
 }
 
 void QmitkMxNMultiWidgetEditor::PartVisible(const berry::IWorkbenchPartReference::Pointer& partRef)
 {
   if (partRef->GetId() == QmitkMxNMultiWidgetEditor::EDITOR_ID)
   {
     const auto& multiWidget = dynamic_cast<QmitkMxNMultiWidget*>(GetMultiWidget());
     if (nullptr != multiWidget)
     {
       multiWidget->ActivateMenuWidget(true);
     }
   }
 }
 
 void QmitkMxNMultiWidgetEditor::OnLayoutSet(int row, int column)
 {
   const auto &multiWidget = dynamic_cast<QmitkMxNMultiWidget*>(GetMultiWidget());
   if (nullptr != multiWidget)
   {
     QmitkAbstractMultiWidgetEditor::OnLayoutSet(row, column);
     multiWidget->AddPlanesToDataStorage();
   }
 }
 
 void QmitkMxNMultiWidgetEditor::OnInteractionSchemeChanged(mitk::InteractionSchemeSwitcher::InteractionScheme scheme)
 {
   const auto &multiWidget = GetMultiWidget();
   if (nullptr == multiWidget)
   {
     return;
   }
 
   if (mitk::InteractionSchemeSwitcher::PACSStandard == scheme)
   {
     m_Impl->m_InteractionSchemeToolBar->setVisible(true);
   }
   else
   {
     m_Impl->m_InteractionSchemeToolBar->setVisible(false);
   }
 
   QmitkAbstractMultiWidgetEditor::OnInteractionSchemeChanged(scheme);
 }
 
 //////////////////////////////////////////////////////////////////////////
 // PRIVATE
 //////////////////////////////////////////////////////////////////////////
 void QmitkMxNMultiWidgetEditor::SetFocus()
 {
   const auto& multiWidget = GetMultiWidget();
   if (nullptr != multiWidget)
   {
     multiWidget->setFocus();
   }
 }
 
 void QmitkMxNMultiWidgetEditor::CreateQtPartControl(QWidget* parent)
 {
   QHBoxLayout *layout = new QHBoxLayout(parent);
   layout->setContentsMargins(0, 0, 0, 0);
 
   auto* preferences = this->GetPreferences();
 
   auto multiWidget = GetMultiWidget();
   if (nullptr == multiWidget)
   {
     multiWidget = new QmitkMxNMultiWidget(parent, 0, nullptr);
 
     // create left toolbar: interaction scheme toolbar to switch how the render window navigation behaves in PACS mode
     if (nullptr == m_Impl->m_InteractionSchemeToolBar)
     {
       m_Impl->m_InteractionSchemeToolBar = new QmitkInteractionSchemeToolBar(parent);
       layout->addWidget(m_Impl->m_InteractionSchemeToolBar);
     }
     m_Impl->m_InteractionSchemeToolBar->SetInteractionEventHandler(multiWidget->GetInteractionEventHandler());
 
     multiWidget->SetDataStorage(GetDataStorage());
     multiWidget->InitializeMultiWidget();
     SetMultiWidget(multiWidget);
   }
 
   layout->addWidget(multiWidget);
 
   // create right toolbar: configuration toolbar to change the render window widget layout
   if (nullptr == m_Impl->m_ConfigurationToolBar)
   {
     m_Impl->m_ConfigurationToolBar = new QmitkMultiWidgetConfigurationToolBar(multiWidget);
     layout->addWidget(m_Impl->m_ConfigurationToolBar);
   }
 
   connect(m_Impl->m_ConfigurationToolBar, &QmitkMultiWidgetConfigurationToolBar::LayoutSet,
           this, &QmitkMxNMultiWidgetEditor::OnLayoutSet);
   connect(m_Impl->m_ConfigurationToolBar, &QmitkMultiWidgetConfigurationToolBar::Synchronized,
           this, &QmitkMxNMultiWidgetEditor::OnSynchronize);
   connect(m_Impl->m_ConfigurationToolBar, &QmitkMultiWidgetConfigurationToolBar::InteractionSchemeChanged,
           this, &QmitkMxNMultiWidgetEditor::OnInteractionSchemeChanged);
   connect(m_Impl->m_ConfigurationToolBar, &QmitkMultiWidgetConfigurationToolBar::SaveLayout,
-    static_cast<QmitkMxNMultiWidget*>(GetMultiWidget()), &QmitkMxNMultiWidget::SaveLayout);
+    static_cast<QmitkMxNMultiWidget*>(GetMultiWidget()), &QmitkMxNMultiWidget::SaveLayout, Qt::DirectConnection);
   connect(m_Impl->m_ConfigurationToolBar, &QmitkMultiWidgetConfigurationToolBar::LoadLayout,
     static_cast<QmitkMxNMultiWidget*>(GetMultiWidget()), &QmitkMxNMultiWidget::LoadLayout);
 
   GetSite()->GetPage()->AddPartListener(this);
 
   OnPreferencesChanged(preferences);
 }
 
 void QmitkMxNMultiWidgetEditor::OnPreferencesChanged(const mitk::IPreferences* preferences)
 {
   const auto& multiWidget = GetMultiWidget();
   if (nullptr == multiWidget)
   {
     return;
   }
 
   // update decoration preferences
   //m_Impl->m_MultiWidgetDecorationManager->DecorationPreferencesChanged(preferences);
 
   int crosshairGapSize = preferences->GetInt("crosshair gap size", 32);
   multiWidget->SetCrosshairGap(crosshairGapSize);
 
   // zooming and panning preferences
   bool constrainedZooming = preferences->GetBool("Use constrained zooming and panning", true);
   mitk::RenderingManager::GetInstance()->SetConstrainedPanningZooming(constrainedZooming);
 
   bool PACSInteractionScheme = preferences->GetBool("PACS like mouse interaction", false);
   OnInteractionSchemeChanged(PACSInteractionScheme ?
     mitk::InteractionSchemeSwitcher::PACSStandard :
     mitk::InteractionSchemeSwitcher::MITKStandard);
 
   mitk::RenderingManager::GetInstance()->RequestUpdateAll();
 }