diff --git a/Plugins/org.mitk.gui.qt.flow.segmentation/src/internal/QmitkSegmentationFlowControlView.cpp b/Plugins/org.mitk.gui.qt.flow.segmentation/src/internal/QmitkSegmentationFlowControlView.cpp
index 6bfa4b5c58..f76633cded 100644
--- a/Plugins/org.mitk.gui.qt.flow.segmentation/src/internal/QmitkSegmentationFlowControlView.cpp
+++ b/Plugins/org.mitk.gui.qt.flow.segmentation/src/internal/QmitkSegmentationFlowControlView.cpp
@@ -1,183 +1,177 @@
 /*============================================================================
 
 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 "org_mitk_gui_qt_flow_segmentation_Activator.h"
 
 // Blueberry
 #include <berryISelectionService.h>
 #include <berryIWorkbenchWindow.h>
 
 #include <itksys/SystemTools.hxx>
 
 //MITK
 #include <mitkBaseApplication.h>
 #include <mitkLabelSetImage.h>
 #include <mitkNodePredicateAnd.h>
 #include <mitkNodePredicateNot.h>
 #include <mitkNodePredicateProperty.h>
 #include <mitkNodePredicateDataType.h>
 #include <mitkIOUtil.h>
 
 // Qmitk
 #include "QmitkSegmentationFlowControlView.h"
 
 // Qt
 #include <QMessageBox>
 #include <QDir>
 
 #include <filesystem>
 
 const std::string QmitkSegmentationFlowControlView::VIEW_ID = "org.mitk.views.flow.control";
 
 QmitkSegmentationFlowControlView::QmitkSegmentationFlowControlView()
     : m_Parent(nullptr)
 {
   auto notHelperObject = mitk::NodePredicateNot::New(
     mitk::NodePredicateProperty::New("helper object"));
 
   m_SegmentationPredicate = mitk::NodePredicateAnd::New(
     mitk::TNodePredicateDataType<mitk::LabelSetImage>::New(),
     notHelperObject);
 
   m_SegmentationTaskListPredicate = mitk::NodePredicateAnd::New(
     mitk::TNodePredicateDataType<mitk::SegmentationTaskList>::New(),
     notHelperObject);
 }
 
 void QmitkSegmentationFlowControlView::SetFocus()
 {
     m_Controls.btnStoreAndAccept->setFocus();
 }
 
 void QmitkSegmentationFlowControlView::CreateQtPartControl(QWidget* parent)
 {
   // create GUI widgets from the Qt Designer's .ui file
   m_Controls.setupUi(parent);
 
   m_Parent = parent;
 
   using Self = QmitkSegmentationFlowControlView;
 
   connect(m_Controls.btnStoreAndAccept, &QPushButton::clicked, this, &Self::OnAcceptButtonPushed);
   connect(m_Controls.segmentationTaskListWidget, &QmitkSegmentationTaskListWidget::ActiveTaskChanged, this, &Self::OnActiveTaskChanged);
   connect(m_Controls.segmentationTaskListWidget, &QmitkSegmentationTaskListWidget::CurrentTaskChanged, this, &Self::OnCurrentTaskChanged);
 
   m_Controls.segmentationTaskListWidget->setVisible(false);
   m_Controls.labelStored->setVisible(false);
   UpdateControls();
 
   m_OutputDir = QString::fromStdString(mitk::BaseApplication::instance().config().getString("flow.outputdir", itksys::SystemTools::GetCurrentWorkingDirectory()));
   m_OutputDir = QDir::fromNativeSeparators(m_OutputDir);
 
   m_FileExtension = QString::fromStdString(mitk::BaseApplication::instance().config().getString("flow.outputextension", "nrrd"));
 }
 
 void QmitkSegmentationFlowControlView::OnAcceptButtonPushed()
 {
   if (m_Controls.segmentationTaskListWidget->isVisible())
   {
     auto* taskList = m_Controls.segmentationTaskListWidget->GetTaskList();
 
     if (taskList != nullptr)
     {
       auto activeTaskIndex = m_Controls.segmentationTaskListWidget->GetActiveTaskIndex();
 
       if (activeTaskIndex.has_value())
       {
         auto segmentationNode = m_Controls.segmentationTaskListWidget->GetSegmentationDataNode(activeTaskIndex.value());
 
         if (segmentationNode != nullptr)
         {
           QApplication::setOverrideCursor(Qt::BusyCursor);
 
           try
           {
             taskList->SaveTask(activeTaskIndex.value(), segmentationNode->GetData());
             m_Controls.segmentationTaskListWidget->OnUnsavedChangesSaved();
           }
           catch (const mitk::Exception& e)
           {
             MITK_ERROR << e;
           }
 
           QApplication::restoreOverrideCursor();
         }
       }
     }
   }
   else
   {
     auto nodes = this->GetDataStorage()->GetSubset(m_SegmentationPredicate);
 
     for (auto node : *nodes)
     {
       QString outputpath = m_OutputDir + "/" + QString::fromStdString(node->GetName()) + "." + m_FileExtension;
       outputpath = QDir::toNativeSeparators(QDir::cleanPath(outputpath));
       mitk::IOUtil::Save(node->GetData(), outputpath.toStdString());
     }
 
     m_Controls.labelStored->setVisible(true);
   }
 }
 
 void QmitkSegmentationFlowControlView::OnActiveTaskChanged(const std::optional<size_t>&)
 {
   this->UpdateControls();
 }
 
-void QmitkSegmentationFlowControlView::OnCurrentTaskChanged(size_t)
+void QmitkSegmentationFlowControlView::OnCurrentTaskChanged(const std::optional<size_t>&)
 {
   this->UpdateControls();
 }
 
 void QmitkSegmentationFlowControlView::UpdateControls()
 {
   auto dataStorage = this->GetDataStorage();
 
   auto hasTaskList = !dataStorage->GetSubset(m_SegmentationTaskListPredicate)->empty();
   m_Controls.segmentationTaskListWidget->setVisible(hasTaskList);
 
   if (hasTaskList)
   {
-    auto activeTaskIndex = m_Controls.segmentationTaskListWidget->GetActiveTaskIndex();
-    auto hasActiveTtask = activeTaskIndex.has_value();
-
-    auto isCurrentTask = hasActiveTtask
-      ? m_Controls.segmentationTaskListWidget->GetCurrentTaskIndex() == activeTaskIndex.value()
-      : false;
-
-    m_Controls.btnStoreAndAccept->setEnabled(hasActiveTtask && isCurrentTask);
+    auto activeTaskIsShown = m_Controls.segmentationTaskListWidget->ActiveTaskIsShown();
+    m_Controls.btnStoreAndAccept->setEnabled(activeTaskIsShown);
   }
   else
   {
     auto hasSegmentation = !dataStorage->GetSubset(m_SegmentationPredicate)->empty();
     m_Controls.btnStoreAndAccept->setEnabled(hasSegmentation);
   }
 }
 
 void QmitkSegmentationFlowControlView::NodeAdded(const mitk::DataNode* node)
 {
   if (dynamic_cast<const mitk::LabelSetImage*>(node->GetData()) != nullptr)
     this->UpdateControls();
 }
 
 void QmitkSegmentationFlowControlView::NodeChanged(const mitk::DataNode* node)
 {
   if (dynamic_cast<const mitk::LabelSetImage*>(node->GetData()) != nullptr)
     this->UpdateControls();
 }
 
 void QmitkSegmentationFlowControlView::NodeRemoved(const mitk::DataNode* node)
 {
   if (dynamic_cast<const mitk::LabelSetImage*>(node->GetData()) != nullptr)
     this->UpdateControls();
 }
diff --git a/Plugins/org.mitk.gui.qt.flow.segmentation/src/internal/QmitkSegmentationFlowControlView.h b/Plugins/org.mitk.gui.qt.flow.segmentation/src/internal/QmitkSegmentationFlowControlView.h
index dfadb80c1e..4a1bc826ce 100644
--- a/Plugins/org.mitk.gui.qt.flow.segmentation/src/internal/QmitkSegmentationFlowControlView.h
+++ b/Plugins/org.mitk.gui.qt.flow.segmentation/src/internal/QmitkSegmentationFlowControlView.h
@@ -1,79 +1,79 @@
 /*============================================================================
 
 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 __Q_MITK_MATCHPOINT_MAPPER_H
 #define __Q_MITK_MATCHPOINT_MAPPER_H
 
 #include <berryISelectionListener.h>
 #include <QmitkAbstractView.h>
 
 #include "mitkNodePredicateBase.h"
 
 #include "ui_QmitkSegmentationFlowControlView.h"
 
 #include <optional>
 
 /*!
   \brief QmitkSegmentationFlowControlView
 
   Class that "controls" the segmentation view. It offers the possibility to accept a segmentation.
   Accepting the segmentation stores the segmentation to the given working directory.
 
   The working directory is specified by command line arguments. If no commandline flag is set the current working directory will be used.
 */
 class QmitkSegmentationFlowControlView : public QmitkAbstractView
 {
     // this is needed for all Qt objects that should have a Qt meta-object
     // (everything that derives from QObject and wants to have signal/slots)
     Q_OBJECT
 
 public:
 
     static const std::string VIEW_ID;
 
     /**
      * Creates smartpointer typedefs
      */
     berryObjectMacro(QmitkSegmentationFlowControlView)
 
     QmitkSegmentationFlowControlView();
 
     void CreateQtPartControl(QWidget *parent) override;
 
 protected slots:
 
     void OnAcceptButtonPushed();
     void OnActiveTaskChanged(const std::optional<size_t>& index);
-    void OnCurrentTaskChanged(size_t index);
+    void OnCurrentTaskChanged(const std::optional<size_t>& index);
 
 protected:
     void SetFocus() override;
 
     void NodeAdded(const mitk::DataNode* node) override;
     void NodeChanged(const mitk::DataNode* node) override;
     void NodeRemoved(const mitk::DataNode* node) override;
 
     void UpdateControls();
 
     Ui::SegmentationFlowControlView m_Controls;
 
 private:
     QWidget *m_Parent;
     mitk::NodePredicateBase::Pointer m_SegmentationPredicate;
     mitk::NodePredicateBase::Pointer m_SegmentationTaskListPredicate;
     QString m_OutputDir;
     QString m_FileExtension;
 };
 
 #endif // MatchPoint_h
 
diff --git a/Plugins/org.mitk.gui.qt.flow.segmentation/src/internal/QmitkSegmentationTaskListWidget.cpp b/Plugins/org.mitk.gui.qt.flow.segmentation/src/internal/QmitkSegmentationTaskListWidget.cpp
index 1c355397e9..1ee3509581 100644
--- a/Plugins/org.mitk.gui.qt.flow.segmentation/src/internal/QmitkSegmentationTaskListWidget.cpp
+++ b/Plugins/org.mitk.gui.qt.flow.segmentation/src/internal/QmitkSegmentationTaskListWidget.cpp
@@ -1,713 +1,737 @@
 /*============================================================================
 
 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 "QmitkSegmentationTaskListWidget.h"
 #include "org_mitk_gui_qt_flow_segmentation_Activator.h"
 
 #include <mitkIDataStorageService.h>
 #include <mitkIOUtil.h>
 #include <mitkLabelSetIOHelper.h>
 #include <mitkLabelSetImageHelper.h>
 #include <mitkNodePredicateDataType.h>
 #include <mitkNodePredicateFunction.h>
 #include <mitkRenderingManager.h>
 #include <mitkSegmentationHelper.h>
 
 #include <QmitkStaticDynamicSegmentationDialog.h>
 #include <QmitkStyleManager.h>
 
 #include <ui_QmitkSegmentationTaskListWidget.h>
 
 #include <QFileSystemWatcher>
 #include <QMessageBox>
 
 #include <filesystem>
 
 namespace
 {
   mitk::DataStorage* GetDataStorage()
   {
     auto* pluginContext = org_mitk_gui_qt_flow_segmentation_Activator::GetContext();
     auto dataStorageServiceReference = pluginContext->getServiceReference<mitk::IDataStorageService>();
 
     if (dataStorageServiceReference)
     {
       auto* dataStorageService = pluginContext->getService<mitk::IDataStorageService>(dataStorageServiceReference);
 
       if (dataStorageService != nullptr)
       {
         auto dataStorageReference = dataStorageService->GetDataStorage();
         pluginContext->ungetService(dataStorageServiceReference);
 
         return dataStorageReference->GetDataStorage();
       }
     }
 
     return nullptr;
   }
 
   std::filesystem::path GetInputLocation(const mitk::BaseData* data)
   {
     std::string result;
 
     if (data != nullptr)
       data->GetPropertyList()->GetStringProperty("MITK.IO.reader.inputlocation", result);
 
     return result;
   }
 
   QString ColorString(const QString& string, const QColor& color, const QColor& backgroundColor = QColor::Invalid)
   {
     if (!color.isValid() && !backgroundColor.isValid())
       return string;
 
     auto result = QStringLiteral("<span style=\"");
     QStringList strings;
 
     if (color.isValid())
       strings << QString("color: %1;").arg(color.name());
 
     if (backgroundColor.isValid())
       strings << QString("background-color: %1;").arg(backgroundColor.name());
 
     result += strings.join(' ') + QString("\">%1</span>").arg(string);
 
     return result;
   }
 }
 
 /* This constructor has three objectives:
  *   1. Do widget initialization that cannot be done in the .ui file
  *   2. Connect signals and slots
  *   3. Explicitly trigger a reset to a valid initial widget state
  */
 QmitkSegmentationTaskListWidget::QmitkSegmentationTaskListWidget(QWidget* parent)
   : QWidget(parent),
     m_Ui(new Ui::QmitkSegmentationTaskListWidget),
     m_FileSystemWatcher(new QFileSystemWatcher(this)),
-    m_CurrentTaskIndex(0),
     m_UnsavedChanges(false)
 {
   m_Ui->setupUi(this);
 
   m_Ui->selectionWidget->SetDataStorage(GetDataStorage());
   m_Ui->selectionWidget->SetSelectionIsOptional(true);
   m_Ui->selectionWidget->SetEmptyInfo(QStringLiteral("Select a segmentation task list"));
   m_Ui->selectionWidget->SetAutoSelectNewNodes(true);
   m_Ui->selectionWidget->SetNodePredicate(mitk::TNodePredicateDataType<mitk::SegmentationTaskList>::New());
 
   m_Ui->progressBar->setStyleSheet(QString("QProgressBar::chunk { background-color: %1; }").arg(QmitkStyleManager::GetIconAccentColor()));
 
   using Self = QmitkSegmentationTaskListWidget;
 
   connect(m_Ui->selectionWidget, &QmitkSingleNodeSelectionWidget::CurrentSelectionChanged, this, &Self::OnSelectionChanged);
   connect(m_Ui->previousButton, &QToolButton::clicked, this, &Self::OnPreviousButtonClicked);
   connect(m_Ui->nextButton, &QToolButton::clicked, this, &Self::OnNextButtonClicked);
   connect(m_Ui->loadButton, &QPushButton::clicked, this, &Self::OnLoadButtonClicked);
 
   connect(m_FileSystemWatcher, &QFileSystemWatcher::directoryChanged, this, &Self::OnResultDirectoryChanged);
 
   this->OnSelectionChanged(m_Ui->selectionWidget->GetSelectedNodes());
 }
 
 QmitkSegmentationTaskListWidget::~QmitkSegmentationTaskListWidget()
 {
 }
 
 mitk::SegmentationTaskList* QmitkSegmentationTaskListWidget::GetTaskList() const
 {
   return m_TaskList;
 }
 
 std::optional<size_t> QmitkSegmentationTaskListWidget::GetActiveTaskIndex() const
 {
   return m_ActiveTaskIndex;
 }
 
-size_t QmitkSegmentationTaskListWidget::GetCurrentTaskIndex() const
+std::optional<size_t> QmitkSegmentationTaskListWidget::GetCurrentTaskIndex() const
 {
   return m_CurrentTaskIndex;
 }
 
 void QmitkSegmentationTaskListWidget::OnUnsavedChangesSaved()
 {
   if (m_UnsavedChanges)
   {
     m_UnsavedChanges = false;
 
     if (this->ActiveTaskIsShown())
       this->UpdateDetailsLabel();
   }
 }
 
 /* Make sure that the widget transitions into a valid state whenever the
  * selection changes.
  */
 void QmitkSegmentationTaskListWidget::OnSelectionChanged(const QmitkSingleNodeSelectionWidget::NodeList& nodes)
 {
   this->UnloadTasks();
   this->ResetControls();
 
   if (!nodes.empty())
   {
     m_TaskListNode = nodes.front();
     auto taskList = dynamic_cast<mitk::SegmentationTaskList*>(m_TaskListNode->GetData());
 
     if (taskList != nullptr)
     {
       this->OnTaskListChanged(taskList);
       return;
     }
   }
 
   this->SetTaskList(nullptr);
   m_TaskListNode = nullptr;
 }
 
 /* Reset all controls to a default state as a common basis for further
  * adjustments.
  */
 void QmitkSegmentationTaskListWidget::ResetControls()
 {
   m_Ui->progressBar->setEnabled(false);
   m_Ui->progressBar->setFormat("");
   m_Ui->progressBar->setValue(0);
   m_Ui->progressBar->setMaximum(1);
 
   m_Ui->previousButton->setEnabled(false);
-
-  m_Ui->loadButton->setEnabled(false);
-  m_Ui->loadButton->setText(QStringLiteral("Load task"));
-
   m_Ui->nextButton->setEnabled(false);
 
-  m_Ui->detailsLabel->clear();
+  this->UpdateLoadButton();
+  this->UpdateDetailsLabel();
 }
 
 /* If the segmentation task changed, reset all member variables to expected
  * default values and reset the file system watcher.
  */
 void QmitkSegmentationTaskListWidget::SetTaskList(mitk::SegmentationTaskList* taskList)
 {
   if (m_TaskList != taskList)
   {
     m_TaskList = taskList;
 
-    this->SetCurrentTaskIndex(0);
+    if (taskList != nullptr)
+    {
+      this->SetCurrentTaskIndex(0);
+    }
+    else
+    {
+      this->SetCurrentTaskIndex(std::nullopt);
+    }
+
     this->ResetFileSystemWatcher();
   }
 }
 
 void QmitkSegmentationTaskListWidget::ResetFileSystemWatcher()
 {
   auto paths = m_FileSystemWatcher->directories();
 
   if (!paths.empty())
     m_FileSystemWatcher->removePaths(paths);
 
   if (m_TaskList.IsNotNull())
   {
     for (const auto& task : *m_TaskList)
     {
       auto resultPath = m_TaskList->GetAbsolutePath(task.GetResult()).remove_filename();
 
       if (!std::filesystem::exists(resultPath))
       {
         try
         {
           std::filesystem::create_directories(resultPath);
         }
         catch (const std::filesystem::filesystem_error& e)
         {
           MITK_ERROR << e.what();
         }
       }
 
       if (std::filesystem::exists(resultPath))
         m_FileSystemWatcher->addPath(QString::fromStdString(resultPath.string()));
     }
   }
 }
 
 void QmitkSegmentationTaskListWidget::OnResultDirectoryChanged(const QString&)
 {
   // TODO: If a segmentation was modified ("Unsaved changes"), saved ("Done"), and then the file is deleted, the status should be "Unsaved changes" instead of "Not done".
   this->UpdateProgressBar();
   this->UpdateDetailsLabel();
 }
 
 void QmitkSegmentationTaskListWidget::UpdateProgressBar()
 {
   int progress = 0;
 
   for (size_t i = 0; i < m_TaskList->GetNumberOfTasks(); ++i)
   {
     if (m_TaskList->IsDone(i))
       ++progress;
   }
 
   m_Ui->progressBar->setValue(progress);
 }
 
-/* Provided that a valid segmentation task is currently selected and the
+/* Provided that a valid segmentation task list is currently selected and the
  * widget is in its default state, update all controls accordingly.
  */
 void QmitkSegmentationTaskListWidget::OnTaskListChanged(mitk::SegmentationTaskList* taskList)
 {
   this->SetTaskList(taskList);
 
   const auto numTasks = taskList->GetNumberOfTasks();
 
   m_Ui->progressBar->setMaximum(numTasks);
   m_Ui->progressBar->setFormat(QStringLiteral("%v/%m Task(s) done"));
   m_Ui->progressBar->setEnabled(true);
 
   this->UpdateProgressBar();
 
   m_Ui->loadButton->setEnabled(true);
 
   if (numTasks > 1)
     m_Ui->nextButton->setEnabled(true);
 }
 
 /* If possible, change the currently displayed task to the previous task.
  * Enable/disable navigation buttons according to the task's position.
  */
 void QmitkSegmentationTaskListWidget::OnPreviousButtonClicked()
 {
   const auto maxIndex = m_TaskList->GetNumberOfTasks() - 1;
+  auto current = m_CurrentTaskIndex.value();
+
+  if (current != 0)
+    this->SetCurrentTaskIndex(current - 1);
 
-  if (m_CurrentTaskIndex != 0)
-    this->SetCurrentTaskIndex(m_CurrentTaskIndex - 1);
+  current = m_CurrentTaskIndex.value();
 
-  if (m_CurrentTaskIndex == 0)
+  if (current == 0)
     m_Ui->previousButton->setEnabled(false);
 
-  if (m_CurrentTaskIndex < maxIndex)
+  if (current < maxIndex)
     m_Ui->nextButton->setEnabled(true);
 }
 
 /* If possible, change the currently displayed task to the next task.
  * Enable/disable navigation buttons according to the task's position.
  */
 void QmitkSegmentationTaskListWidget::OnNextButtonClicked()
 {
   const auto maxIndex = m_TaskList->GetNumberOfTasks() - 1;
+  auto current = m_CurrentTaskIndex.value();
+
+  if (current < maxIndex)
+    this->SetCurrentTaskIndex(current + 1);
 
-  if (m_CurrentTaskIndex < maxIndex)
-    this->SetCurrentTaskIndex(m_CurrentTaskIndex + 1);
+  current = m_CurrentTaskIndex.value();
 
-  if (m_CurrentTaskIndex != 0)
+  if (current != 0)
     m_Ui->previousButton->setEnabled(true);
 
-  if (m_CurrentTaskIndex >= maxIndex)
+  if (current >= maxIndex)
     m_Ui->nextButton->setEnabled(false);
 }
 
 /* Update affected controls when the currently displayed task changed.
  */
 void QmitkSegmentationTaskListWidget::OnCurrentTaskChanged()
 {
   this->UpdateLoadButton();
   this->UpdateDetailsLabel();
 }
 
 /* Update the load button according to the currently displayed task.
  */
 void QmitkSegmentationTaskListWidget::UpdateLoadButton()
 {
-  const auto current = m_CurrentTaskIndex;
-
   auto text = !this->ActiveTaskIsShown()
     ? QStringLiteral("Load task")
     : QStringLiteral("Task");
 
-  if (m_TaskList.IsNotNull())
+  if (m_CurrentTaskIndex.has_value())
   {
-    text += QString(" %1/%2").arg(current + 1).arg(m_TaskList->GetNumberOfTasks());
+    const auto current = m_CurrentTaskIndex.value();
 
-    if (m_TaskList->HasName(current))
-      text += QStringLiteral(":\n") + QString::fromStdString(m_TaskList->GetName(current));
+    if (m_TaskList.IsNotNull())
+    {
+      text += QString(" %1/%2").arg(current + 1).arg(m_TaskList->GetNumberOfTasks());
+
+      if (m_TaskList->HasName(current))
+        text += QStringLiteral(":\n") + QString::fromStdString(m_TaskList->GetName(current));
+    }
+
+    m_Ui->loadButton->setDisabled(this->ActiveTaskIsShown());
+  }
+  else
+  {
+    m_Ui->loadButton->setEnabled(false);
   }
 
-  m_Ui->loadButton->setDisabled(this->ActiveTaskIsShown());
   m_Ui->loadButton->setText(text);
 }
 
 /* Update the details label according to the currently display task.
  * The text is composed of the status of the task and a variable number
  * of text blocks according to the optional values provided by the task.
  */
 void QmitkSegmentationTaskListWidget::UpdateDetailsLabel()
 {
-  const auto current = m_CurrentTaskIndex;
+  if (!m_CurrentTaskIndex.has_value())
+  {
+    m_Ui->detailsLabel->clear();
+    return;
+  }
+
+  const auto current = m_CurrentTaskIndex.value();
   bool isDone = m_TaskList->IsDone(current);
 
   auto details = QString("<p><b>Status: %1</b> / <b>").arg(this->ActiveTaskIsShown()
     ? ColorString("Active", Qt::white, QColor(Qt::green).darker())
     : ColorString("Inactive", Qt::white, QColor(Qt::red).darker()));
 
   if (m_UnsavedChanges && this->ActiveTaskIsShown())
   {
     details += QString("%1</b></p>").arg(ColorString("Unsaved changes", Qt::white, QColor(Qt::red).darker()));
   }
   else
   {
     details += QString("%1</b></p>").arg(isDone
       ? ColorString("Done", Qt::white, QColor(Qt::green).darker())
       : ColorString("Not done", Qt::white, QColor(Qt::red).darker()));
   }
 
   if (m_TaskList->HasDescription(current))
     details += QString("<p><b>Description:</b> %1</p>").arg(QString::fromStdString(m_TaskList->GetDescription(current)));
 
   QStringList stringList;
 
   if (m_TaskList->HasImage(current))
     stringList << QString::fromStdString("<b>Image:</b> " + m_TaskList->GetImage(current));
 
   if (m_TaskList->HasSegmentation(current))
     stringList << QString::fromStdString("<b>Segmentation:</b> " + m_TaskList->GetSegmentation(current));
 
   if (m_TaskList->HasLabelName(current))
     stringList << QString::fromStdString("<b>Label name:</b> " + m_TaskList->GetLabelName(current));
 
   if (m_TaskList->HasPreset(current))
     stringList << QString::fromStdString("<b>Label set preset:</b> " + m_TaskList->GetPreset(current));
 
   if (m_TaskList->HasDynamic(current))
     stringList << QString("<b>Segmentation type:</b> %1").arg(m_TaskList->GetDynamic(current) ? "Dynamic" : "Static");
 
   if (!stringList.empty())
     details += QString("<p>%1</p>").arg(stringList.join(QStringLiteral("<br>")));
 
   m_Ui->detailsLabel->setText(details);
 }
 
 /* Load/activate the currently displayed task. Unload all data nodes from
  * previously active tasks first, but spare and reuse the image if possible.
  */
 void QmitkSegmentationTaskListWidget::OnLoadButtonClicked()
 {
   if (!this->HandleUnsavedChanges() || m_UnsavedChanges)
     return;
 
   m_Ui->loadButton->setEnabled(false);
 
   QApplication::setOverrideCursor(Qt::BusyCursor);
-  this->LoadTask(this->GetImageDataNode(m_CurrentTaskIndex));
+  this->LoadTask(this->GetImageDataNode(m_CurrentTaskIndex.value()));
   QApplication::restoreOverrideCursor();
 }
 
 /* If present, return the image data node for the task with the specified
  * index. Otherwise, return nullptr.
  */
 mitk::DataNode* QmitkSegmentationTaskListWidget::GetImageDataNode(size_t index) const
 {
   const auto imagePath = m_TaskList->GetAbsolutePath(m_TaskList->GetImage(index));
 
   auto imageNodes = GetDataStorage()->GetDerivations(m_TaskListNode, mitk::NodePredicateFunction::New([imagePath](const mitk::DataNode* node) {
     return imagePath == GetInputLocation(node->GetData());
   }));
 
   return !imageNodes->empty()
     ? imageNodes->front()
     : nullptr;
 }
 
 /* If present, return the segmentation data node for the task with the
  * specified index. Otherwise, return nullptr.
  */
 mitk::DataNode* QmitkSegmentationTaskListWidget::GetSegmentationDataNode(size_t index) const
 {
   const auto* imageNode = this->GetImageDataNode(index);
 
   if (imageNode != nullptr)
   {
     auto segmentations = GetDataStorage()->GetDerivations(imageNode, mitk::TNodePredicateDataType<mitk::LabelSetImage>::New());
 
     if (!segmentations->empty())
       return segmentations->front();
   }
 
   return nullptr;
 }
 
 /* Unload all task data nodes but spare the passed image data node.
  */
 void QmitkSegmentationTaskListWidget::UnloadTasks(const mitk::DataNode* skip)
 {
   this->UnsubscribeFromActiveSegmentation();
 
   if (m_TaskListNode.IsNotNull())
   {
     mitk::DataStorage::Pointer dataStorage = GetDataStorage();
 
     auto imageNodes = dataStorage->GetDerivations(m_TaskListNode, mitk::TNodePredicateDataType<mitk::Image>::New());
 
     for (auto imageNode : *imageNodes)
     {
       dataStorage->Remove(dataStorage->GetDerivations(imageNode, nullptr, false));
 
       if (imageNode != skip)
         dataStorage->Remove(imageNode);
     }
   }
 
   this->SetActiveTaskIndex(std::nullopt);
 }
 
 /* Load/activate the currently displayed task. The task must specify
  * an image. The segmentation is either created from scratch with an optional
  * name for the first label, possibly based on a label set preset specified by
  * the task, or loaded as specified by the task. If a result file does
  * exist, it is chosen as segmentation instead.
  */
 void QmitkSegmentationTaskListWidget::LoadTask(mitk::DataNode::Pointer imageNode)
 {
   this->UnloadTasks(imageNode);
 
-  const auto current = m_CurrentTaskIndex;
+  const auto current = m_CurrentTaskIndex.value();
 
   mitk::Image::Pointer image;
   mitk::LabelSetImage::Pointer segmentation;
 
   try
   {
     if (imageNode.IsNull())
     {
       const auto path = m_TaskList->GetAbsolutePath(m_TaskList->GetImage(current));
       image = mitk::IOUtil::Load<mitk::Image>(path.string());
     }
 
     const auto path = m_TaskList->GetAbsolutePath(m_TaskList->GetResult(current));
 
     if (std::filesystem::exists(path))
     {
       segmentation = mitk::IOUtil::Load<mitk::LabelSetImage>(path.string());
     }
     else if (m_TaskList->HasSegmentation(current))
     {
       const auto path = m_TaskList->GetAbsolutePath(m_TaskList->GetSegmentation(current));
       segmentation = mitk::IOUtil::Load<mitk::LabelSetImage>(path.string());
     }
   }
   catch (const mitk::Exception&)
   {
     return;
   }
 
   auto dataStorage = GetDataStorage();
 
   if (imageNode.IsNull())
   {
     imageNode = mitk::DataNode::New();
     imageNode->SetData(image);
 
     dataStorage->Add(imageNode, m_TaskListNode);
 
     mitk::RenderingManager::GetInstance()->InitializeViews(image->GetTimeGeometry());
   }
   else
   {
     image = static_cast<mitk::Image*>(imageNode->GetData());
   }
 
   auto name = "Task " + std::to_string(current + 1);
   imageNode->SetName(name);
 
   if (segmentation.IsNull())
   {
     mitk::Image::ConstPointer templateImage = image;
 
     if (templateImage->GetDimension() > 3)
     {
       if (m_TaskList->HasDynamic(current))
       {
         if (!m_TaskList->GetDynamic(current))
           templateImage = mitk::SegmentationHelper::GetStaticSegmentationTemplate(image);
       }
       else
       {
         QmitkStaticDynamicSegmentationDialog dialog(this);
         dialog.SetReferenceImage(templateImage);
         dialog.exec();
 
         templateImage = dialog.GetSegmentationTemplate();
       }
     }
 
     auto segmentationNode = mitk::LabelSetImageHelper::CreateNewSegmentationNode(imageNode, templateImage, name);
     segmentation = static_cast<mitk::LabelSetImage*>(segmentationNode->GetData());
 
     if (m_TaskList->HasPreset(current))
     {
       const auto path = m_TaskList->GetAbsolutePath(m_TaskList->GetPreset(current));
       mitk::LabelSetIOHelper::LoadLabelSetImagePreset(path.string(), segmentation);
     }
     else
     {
       auto label = mitk::LabelSetImageHelper::CreateNewLabel(segmentation);
 
       if (m_TaskList->HasLabelName(current))
         label->SetName(m_TaskList->GetLabelName(current));
 
       segmentation->GetActiveLabelSet()->AddLabel(label);
     }
 
     dataStorage->Add(segmentationNode, imageNode);
   }
   else
   {
     auto segmentationNode = mitk::DataNode::New();
     segmentationNode->SetName(name);
     segmentationNode->SetData(segmentation);
 
     dataStorage->Add(segmentationNode, imageNode);
   }
 
   m_UnsavedChanges = false;
 
   this->SetActiveTaskIndex(current);
   this->SubscribeToActiveSegmentation();
 
   this->OnCurrentTaskChanged();
 }
 
 void QmitkSegmentationTaskListWidget::SubscribeToActiveSegmentation()
 {
   if (m_ActiveTaskIndex.has_value())
   {
     auto segmentationNode = this->GetSegmentationDataNode(m_ActiveTaskIndex.value());
 
     if (segmentationNode != nullptr)
     {
       auto segmentation = static_cast<mitk::LabelSetImage*>(segmentationNode->GetData());
 
       auto command = itk::SimpleMemberCommand<QmitkSegmentationTaskListWidget>::New();
       command->SetCallbackFunction(this, &QmitkSegmentationTaskListWidget::OnSegmentationModified);
 
       m_SegmentationModifiedObserverTag = segmentation->AddObserver(itk::ModifiedEvent(), command);
     }
   }
 }
 
 void QmitkSegmentationTaskListWidget::UnsubscribeFromActiveSegmentation()
 {
   if (m_ActiveTaskIndex.has_value() && m_SegmentationModifiedObserverTag.has_value())
   {
     auto segmentationNode = this->GetSegmentationDataNode(m_ActiveTaskIndex.value());
 
     if (segmentationNode != nullptr)
     {
       auto segmentation = static_cast<mitk::LabelSetImage*>(segmentationNode->GetData());
       segmentation->RemoveObserver(m_SegmentationModifiedObserverTag.value());
     }
 
     m_SegmentationModifiedObserverTag.reset();
   }
 }
 
 void QmitkSegmentationTaskListWidget::OnSegmentationModified()
 {
   if (!m_UnsavedChanges)
   {
     m_UnsavedChanges = true;
 
     if (m_ActiveTaskIndex.value() == m_CurrentTaskIndex)
       this->UpdateDetailsLabel();
   }
 }
 
 void QmitkSegmentationTaskListWidget::SetActiveTaskIndex(const std::optional<size_t>& index)
 {
   if (m_ActiveTaskIndex != index)
   {
     m_ActiveTaskIndex = index;
     emit ActiveTaskChanged(m_ActiveTaskIndex);
   }
 }
 
-void QmitkSegmentationTaskListWidget::SetCurrentTaskIndex(size_t index)
+void QmitkSegmentationTaskListWidget::SetCurrentTaskIndex(const std::optional<size_t>& index)
 {
   if (m_CurrentTaskIndex != index)
   {
     m_CurrentTaskIndex = index;
     this->OnCurrentTaskChanged();
     emit CurrentTaskChanged(m_CurrentTaskIndex);
   }
 }
 
 bool QmitkSegmentationTaskListWidget::ActiveTaskIsShown() const
 {
-  return m_ActiveTaskIndex.has_value() && m_ActiveTaskIndex == m_CurrentTaskIndex;
+  return m_ActiveTaskIndex.has_value() && m_CurrentTaskIndex.has_value() && m_ActiveTaskIndex == m_CurrentTaskIndex;
 }
 
 bool QmitkSegmentationTaskListWidget::HandleUnsavedChanges()
 {
   if (m_UnsavedChanges)
   {
     const auto active = m_ActiveTaskIndex.value();
-    const auto current = m_CurrentTaskIndex;
+    const auto current = m_CurrentTaskIndex.value();
 
     auto title = QString("Load task %1").arg(current + 1);
 
     if (m_TaskList->HasName(current))
       title += ": " + QString::fromStdString(m_TaskList->GetName(current));
 
     auto text = QString("The currently active task %1 ").arg(active + 1);
 
     if (m_TaskList->HasName(active))
       text += "(" + QString::fromStdString(m_TaskList->GetName(active)) + ") ";
 
     text += "has unsaved changes.";
 
     auto reply = QMessageBox::question(this, title, text, QMessageBox::Save | QMessageBox::Discard | QMessageBox::Cancel, QMessageBox::Cancel);
 
     switch (reply)
     {
     case QMessageBox::Save:
       this->SaveActiveTask();
       break;
 
     case QMessageBox::Discard:
       m_UnsavedChanges = false;
       break;
 
     default:
       return false;
     }
   }
 
   return true;
 }
 
 void QmitkSegmentationTaskListWidget::SaveActiveTask()
 {
   if (!m_ActiveTaskIndex.has_value())
     return;
 
   QApplication::setOverrideCursor(Qt::BusyCursor);
 
   try
   {
     const auto active = m_ActiveTaskIndex.value();
     m_TaskList->SaveTask(active, this->GetSegmentationDataNode(active)->GetData());
     this->OnUnsavedChangesSaved();
   }
   catch (const mitk::Exception& e)
   {
     MITK_ERROR << e;
   }
 
   QApplication::restoreOverrideCursor();
 }
diff --git a/Plugins/org.mitk.gui.qt.flow.segmentation/src/internal/QmitkSegmentationTaskListWidget.h b/Plugins/org.mitk.gui.qt.flow.segmentation/src/internal/QmitkSegmentationTaskListWidget.h
index 57d11ee0be..f1cf781021 100644
--- a/Plugins/org.mitk.gui.qt.flow.segmentation/src/internal/QmitkSegmentationTaskListWidget.h
+++ b/Plugins/org.mitk.gui.qt.flow.segmentation/src/internal/QmitkSegmentationTaskListWidget.h
@@ -1,87 +1,87 @@
 /*============================================================================
 
 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 QmitkSegmentationTaskListWidget_h
 #define QmitkSegmentationTaskListWidget_h
 
 #include <mitkSegmentationTaskList.h>
 
 #include <MitkSegmentationUIExports.h>
 
 #include <QmitkSingleNodeSelectionWidget.h>
 
 #include <QWidget>
 
 #include <optional>
 
 class QFileSystemWatcher;
 
 namespace Ui
 {
   class QmitkSegmentationTaskListWidget;
 }
 
 class QmitkSegmentationTaskListWidget : public QWidget
 {
   Q_OBJECT
 
 public:
   explicit QmitkSegmentationTaskListWidget(QWidget* parent = nullptr);
   ~QmitkSegmentationTaskListWidget() override;
 
   mitk::SegmentationTaskList* GetTaskList() const;
   std::optional<size_t> GetActiveTaskIndex() const;
-  size_t GetCurrentTaskIndex() const;
+  std::optional<size_t> GetCurrentTaskIndex() const;
   mitk::DataNode* GetSegmentationDataNode(size_t index) const;
   void OnUnsavedChangesSaved();
+  bool ActiveTaskIsShown() const;
 
 signals:
   void ActiveTaskChanged(const std::optional<size_t>& index);
-  void CurrentTaskChanged(size_t index);
+  void CurrentTaskChanged(const std::optional<size_t>& index);
 
 private:
   void OnSelectionChanged(const QmitkSingleNodeSelectionWidget::NodeList& nodes);
   void ResetControls();
   void SetTaskList(mitk::SegmentationTaskList* task);
   void ResetFileSystemWatcher();
   void OnResultDirectoryChanged(const QString&);
   void UpdateProgressBar();
   void OnTaskListChanged(mitk::SegmentationTaskList* task);
   void OnPreviousButtonClicked();
   void OnNextButtonClicked();
   void OnCurrentTaskChanged();
   void UpdateLoadButton();
   void UpdateDetailsLabel();
   void OnLoadButtonClicked();
   mitk::DataNode* GetImageDataNode(size_t index) const;
   void UnloadTasks(const mitk::DataNode* skip = nullptr);
   void LoadTask(mitk::DataNode::Pointer imageNode = nullptr);
   void SubscribeToActiveSegmentation();
   void UnsubscribeFromActiveSegmentation();
   void OnSegmentationModified();
   void SetActiveTaskIndex(const std::optional<size_t>& index);
-  void SetCurrentTaskIndex(size_t index);
-  bool ActiveTaskIsShown() const;
+  void SetCurrentTaskIndex(const std::optional<size_t>& index);
   bool HandleUnsavedChanges();
   void SaveActiveTask();
 
   Ui::QmitkSegmentationTaskListWidget* m_Ui;
   QFileSystemWatcher* m_FileSystemWatcher;
   mitk::SegmentationTaskList::Pointer m_TaskList;
   mitk::DataNode::Pointer m_TaskListNode;
-  size_t m_CurrentTaskIndex;
+  std::optional<size_t> m_CurrentTaskIndex;
   std::optional<size_t> m_ActiveTaskIndex;
   std::optional<unsigned long> m_SegmentationModifiedObserverTag;
   bool m_UnsavedChanges;
 };
 
 #endif