diff --git a/src/Mod/PartDesign/Gui/TaskChamferParameters.cpp b/src/Mod/PartDesign/Gui/TaskChamferParameters.cpp
index b860b160ee..baf69e1b7f 100644
--- a/src/Mod/PartDesign/Gui/TaskChamferParameters.cpp
+++ b/src/Mod/PartDesign/Gui/TaskChamferParameters.cpp
@@ -162,13 +162,16 @@ void TaskChamferParameters::onSelectionChanged(const Gui::SelectionChanges& msg)
 
 void TaskChamferParameters::onCheckBoxUseAllEdgesToggled(bool checked)
 {
-    if(checked)
-        setSelectionMode(none);
-    PartDesign::Chamfer* pcChamfer = static_cast<PartDesign::Chamfer*>(DressUpView->getObject());
-    ui->buttonRefSel->setEnabled(!checked);
-    ui->listWidgetReferences->setEnabled(!checked);
-    pcChamfer->UseAllEdges.setValue(checked);
-    pcChamfer->getDocument()->recomputeFeature(pcChamfer);
+    if (auto chamfer = getObject<PartDesign::Chamfer>()) {
+        if (checked) {
+            setSelectionMode(none);
+        }
+
+        ui->buttonRefSel->setEnabled(!checked);
+        ui->listWidgetReferences->setEnabled(!checked);
+        chamfer->UseAllEdges.setValue(checked);
+        chamfer->recomputeFeature();
+    }
 }
 
 void TaskChamferParameters::setButtons(const selectionModes mode)
@@ -189,58 +192,63 @@ void TaskChamferParameters::onAddAllEdges()
 
 void TaskChamferParameters::onTypeChanged(int index)
 {
-    setSelectionMode(none);
-    PartDesign::Chamfer* pcChamfer = static_cast<PartDesign::Chamfer*>(DressUpView->getObject());
-    pcChamfer->ChamferType.setValue(index);
-    ui->stackedWidget->setCurrentIndex(index);
-    ui->flipDirection->setEnabled(index != 0); // Enable if type is not "Equal distance"
-    pcChamfer->getDocument()->recomputeFeature(pcChamfer);
-    // hide the chamfer if there was a computation error
-    hideOnError();
+    if (auto chamfer = getObject<PartDesign::Chamfer>()) {
+        setSelectionMode(none);
+        chamfer->ChamferType.setValue(index);
+        ui->stackedWidget->setCurrentIndex(index);
+        ui->flipDirection->setEnabled(index != 0); // Enable if type is not "Equal distance"
+        chamfer->recomputeFeature();
+        // hide the chamfer if there was a computation error
+        hideOnError();
+    }
 }
 
 void TaskChamferParameters::onSizeChanged(double len)
 {
-    setSelectionMode(none);
-    PartDesign::Chamfer* pcChamfer = static_cast<PartDesign::Chamfer*>(DressUpView->getObject());
-    setupTransaction();
-    pcChamfer->Size.setValue(len);
-    pcChamfer->getDocument()->recomputeFeature(pcChamfer);
-    // hide the chamfer if there was a computation error
-    hideOnError();
+    if (auto chamfer = getObject<PartDesign::Chamfer>()) {
+        setSelectionMode(none);
+        setupTransaction();
+        chamfer->Size.setValue(len);
+        chamfer->recomputeFeature();
+        // hide the chamfer if there was a computation error
+        hideOnError();
+    }
 }
 
 void TaskChamferParameters::onSize2Changed(double len)
 {
-    setSelectionMode(none);
-    PartDesign::Chamfer* pcChamfer = static_cast<PartDesign::Chamfer*>(DressUpView->getObject());
-    setupTransaction();
-    pcChamfer->Size2.setValue(len);
-    pcChamfer->getDocument()->recomputeFeature(pcChamfer);
-    // hide the chamfer if there was a computation error
-    hideOnError();
+    if (auto chamfer = getObject<PartDesign::Chamfer>()) {
+        setSelectionMode(none);
+        setupTransaction();
+        chamfer->Size2.setValue(len);
+        chamfer->recomputeFeature();
+        // hide the chamfer if there was a computation error
+        hideOnError();
+    }
 }
 
 void TaskChamferParameters::onAngleChanged(double angle)
 {
-    setSelectionMode(none);
-    PartDesign::Chamfer* pcChamfer = static_cast<PartDesign::Chamfer*>(DressUpView->getObject());
-    setupTransaction();
-    pcChamfer->Angle.setValue(angle);
-    pcChamfer->getDocument()->recomputeFeature(pcChamfer);
-    // hide the chamfer if there was a computation error
-    hideOnError();
+    if (auto chamfer = getObject<PartDesign::Chamfer>()) {
+        setSelectionMode(none);
+        setupTransaction();
+        chamfer->Angle.setValue(angle);
+        chamfer->recomputeFeature();
+        // hide the chamfer if there was a computation error
+        hideOnError();
+    }
 }
 
 void TaskChamferParameters::onFlipDirection(bool flip)
 {
-    setSelectionMode(none);
-    PartDesign::Chamfer* pcChamfer = static_cast<PartDesign::Chamfer*>(DressUpView->getObject());
-    setupTransaction();
-    pcChamfer->FlipDirection.setValue(flip);
-    pcChamfer->getDocument()->recomputeFeature(pcChamfer);
-    // hide the chamfer if there was a computation error
-    hideOnError();
+    if (auto chamfer = getObject<PartDesign::Chamfer>()) {
+        setSelectionMode(none);
+        setupTransaction();
+        chamfer->FlipDirection.setValue(flip);
+        chamfer->recomputeFeature();
+        // hide the chamfer if there was a computation error
+        hideOnError();
+    }
 }
 
 int TaskChamferParameters::getType() const
@@ -295,13 +303,9 @@ void TaskChamferParameters::changeEvent(QEvent *e)
 
 void TaskChamferParameters::apply()
 {
-    std::string name = DressUpView->getObject()->getNameInDocument();
+    auto chamfer = getObject<PartDesign::Chamfer>();
 
-    //Gui::Command::openCommand(QT_TRANSLATE_NOOP("Command", "Chamfer changed"));
-
-    PartDesign::Chamfer* pcChamfer = static_cast<PartDesign::Chamfer*>(DressUpView->getObject());
-
-    const int chamfertype = pcChamfer->ChamferType.getValue();
+    const int chamfertype = chamfer->ChamferType.getValue();
 
     switch(chamfertype) {
 
diff --git a/src/Mod/PartDesign/Gui/TaskDraftParameters.cpp b/src/Mod/PartDesign/Gui/TaskDraftParameters.cpp
index ef5eac6fa9..5759661edf 100644
--- a/src/Mod/PartDesign/Gui/TaskDraftParameters.cpp
+++ b/src/Mod/PartDesign/Gui/TaskDraftParameters.cpp
@@ -126,9 +126,9 @@ void TaskDraftParameters::onSelectionChanged(const Gui::SelectionChanges& msg)
             referenceSelected(msg, ui->listWidgetReferences);
         }
         else if (selectionMode == plane) {
-            PartDesign::Draft* pcDraft = static_cast<PartDesign::Draft*>(DressUpView->getObject());
+            auto pcDraft = getObject<PartDesign::Draft>();
             std::vector<std::string> planes;
-            App::DocumentObject* selObj;
+            App::DocumentObject* selObj {};
             getReferencedSelection(pcDraft, msg, selObj, planes);
             if(!selObj)
                 return;
@@ -138,12 +138,12 @@ void TaskDraftParameters::onSelectionChanged(const Gui::SelectionChanges& msg)
 
             pcDraft->getDocument()->recomputeFeature(pcDraft);
             // highlight existing references for possible further selections
-            DressUpView->highlightReferences(true);
+            getDressUpView()->highlightReferences(true);
             // hide the draft if there was a computation error
             hideOnError();
         } 
         else if (selectionMode == line) {
-            PartDesign::Draft* pcDraft = static_cast<PartDesign::Draft*>(DressUpView->getObject());
+            auto pcDraft = getObject<PartDesign::Draft>();
             std::vector<std::string> edges;
             App::DocumentObject* selObj;
             getReferencedSelection(pcDraft, msg, selObj, edges);
@@ -155,7 +155,7 @@ void TaskDraftParameters::onSelectionChanged(const Gui::SelectionChanges& msg)
 
             pcDraft->getDocument()->recomputeFeature(pcDraft);
             // highlight existing references for possible further selections
-            DressUpView->highlightReferences(true);
+            getDressUpView()->highlightReferences(true);
             // hide the draft if there was a computation error
             hideOnError();
         }
@@ -204,7 +204,7 @@ void TaskDraftParameters::getPlane(App::DocumentObject*& obj, std::vector<std::s
 {
     sub = std::vector<std::string>(1,"");
     QStringList parts = ui->linePlane->text().split(QChar::fromLatin1(':'));
-    obj = DressUpView->getObject()->getDocument()->getObject(parts[0].toStdString().c_str());
+    obj = getObject()->getDocument()->getObject(parts[0].toStdString().c_str());
     if (parts.size() > 1)
         sub[0] = parts[1].toStdString();
 }
@@ -213,20 +213,21 @@ void TaskDraftParameters::getLine(App::DocumentObject*& obj, std::vector<std::st
 {
     sub = std::vector<std::string>(1,"");
     QStringList parts = ui->lineLine->text().split(QChar::fromLatin1(':'));
-    obj = DressUpView->getObject()->getDocument()->getObject(parts[0].toStdString().c_str());
+    obj = getObject()->getDocument()->getObject(parts[0].toStdString().c_str());
     if (parts.size() > 1)
         sub[0] = parts[1].toStdString();
 }
 
 void TaskDraftParameters::onAngleChanged(double angle)
 {
-    setButtons(none);
-    PartDesign::Draft* pcDraft = static_cast<PartDesign::Draft*>(DressUpView->getObject());
-    setupTransaction();
-    pcDraft->Angle.setValue(angle);
-    pcDraft->getDocument()->recomputeFeature(pcDraft);
-    // hide the draft if there was a computation error
-    hideOnError();
+    if (auto draft = getObject<PartDesign::Draft>()) {
+        setButtons(none);
+        setupTransaction();
+        draft->Angle.setValue(angle);
+        draft->recomputeFeature();
+        // hide the draft if there was a computation error
+        hideOnError();
+    }
 }
 
 double TaskDraftParameters::getAngle() const
@@ -234,14 +235,16 @@ double TaskDraftParameters::getAngle() const
     return ui->draftAngle->value().getValue();
 }
 
-void TaskDraftParameters::onReversedChanged(const bool on) {
-    setButtons(none);
-    PartDesign::Draft* pcDraft = static_cast<PartDesign::Draft*>(DressUpView->getObject());
-    setupTransaction();
-    pcDraft->Reversed.setValue(on);
-    pcDraft->getDocument()->recomputeFeature(pcDraft);
-    // hide the draft if there was a computation error
-    hideOnError();
+void TaskDraftParameters::onReversedChanged(const bool on)
+{
+    if (auto draft = getObject<PartDesign::Draft>()) {
+        setButtons(none);
+        setupTransaction();
+        draft->Reversed.setValue(on);
+        draft->recomputeFeature();
+        // hide the draft if there was a computation error
+        hideOnError();
+    }
 }
 
 bool TaskDraftParameters::getReversed() const
diff --git a/src/Mod/PartDesign/Gui/TaskDressUpParameters.cpp b/src/Mod/PartDesign/Gui/TaskDressUpParameters.cpp
index 02bb857985..dc2bd94bbc 100644
--- a/src/Mod/PartDesign/Gui/TaskDressUpParameters.cpp
+++ b/src/Mod/PartDesign/Gui/TaskDressUpParameters.cpp
@@ -60,11 +60,11 @@ TaskDressUpParameters::TaskDressUpParameters(ViewProviderDressUp *DressUpView, b
               true,
               parent)
     , proxy(nullptr)
-    , DressUpView(DressUpView)
     , deleteAction(nullptr)
     , addAllEdgesAction(nullptr)
     , allowFaces(selectFaces)
     , allowEdges(selectEdges)
+    , DressUpView(DressUpView)
 {
     // remember initial transaction ID
     App::GetApplication().getActiveTransaction(&transactionID);
@@ -93,7 +93,7 @@ const QString TaskDressUpParameters::btnSelectStr()
 
 void TaskDressUpParameters::setupTransaction()
 {
-    if (!DressUpView)
+    if (DressUpView.expired())
         return;
 
     int tid = 0;
@@ -143,7 +143,7 @@ void TaskDressUpParameters::addAllEdges(QListWidget* widget)
 #ifdef FC_USE_TNP_FIX
     Q_UNUSED(widget)
 
-    if (!DressUpView) {
+    if (DressUpView.expired()) {
         return;
     }
 
@@ -401,18 +401,31 @@ void TaskDressUpParameters::showObject()
     }
 }
 
+ViewProviderDressUp* TaskDressUpParameters::getDressUpView() const
+{
+    return DressUpView.expired() ? nullptr : DressUpView.get();
+}
+
 Part::Feature* TaskDressUpParameters::getBase() const
 {
-    PartDesign::DressUp* pcDressUp = static_cast<PartDesign::DressUp*>(DressUpView->getObject());
-    // Unlikely but this may throw an exception in case we are started to edit an object which base feature
-    // was deleted. This exception will be likely unhandled inside the dialog and pass upper, But an error
-    // message inside the report view is better than a SEGFAULT.
-    // Generally this situation should be prevented in ViewProviderDressUp::setEdit()
-    return pcDressUp->getBaseObject();
+    if (ViewProviderDressUp* vp = getDressUpView()) {
+        auto dressUp = dynamic_cast<PartDesign::DressUp*>(vp->getObject());
+        // Unlikely but this may throw an exception in case we are started to edit an object which
+        // base feature was deleted. This exception will be likely unhandled inside the dialog and
+        // pass upper. But an error message inside the report view is better than a SEGFAULT.
+        // Generally this situation should be prevented in ViewProviderDressUp::setEdit()
+        return dressUp->getBaseObject();
+    }
+
+    return nullptr;
 }
 
 void TaskDressUpParameters::setSelectionMode(selectionModes mode)
 {
+    if (DressUpView.expired()) {
+        return;
+    }
+
     selectionMode = mode;
     setButtons(mode);
 
diff --git a/src/Mod/PartDesign/Gui/TaskDressUpParameters.h b/src/Mod/PartDesign/Gui/TaskDressUpParameters.h
index 4036f72be2..8173309acd 100644
--- a/src/Mod/PartDesign/Gui/TaskDressUpParameters.h
+++ b/src/Mod/PartDesign/Gui/TaskDressUpParameters.h
@@ -24,6 +24,7 @@
 #ifndef GUI_TASKVIEW_TaskDressUpParameters_H
 #define GUI_TASKVIEW_TaskDressUpParameters_H
 
+#include <Gui/DocumentObserver.h>
 #include <Gui/TaskView/TaskView.h>
 #include <Mod/PartDesign/App/FeatureDressUp.h>
 
@@ -87,12 +88,20 @@ protected:
     virtual void setButtons(const selectionModes mode) = 0;
     static void removeItemFromListWidget(QListWidget* widget, const char* itemstr);
 
-    ViewProviderDressUp* getDressUpView() const
-    { return DressUpView; }
+    ViewProviderDressUp* getDressUpView() const;
+
+    template<typename T = App::DocumentObject> T* getObject() const
+    {
+        static_assert(std::is_base_of<App::DocumentObject, T>::value, "Wrong template argument");
+        if (!DressUpView.expired()) {
+            return dynamic_cast<T*>(DressUpView->getObject());
+        }
+
+        return nullptr;
+    }
 
 protected:
     QWidget* proxy;
-    ViewProviderDressUp *DressUpView;
     QAction* deleteAction;
     QAction* addAllEdgesAction;
 
@@ -102,6 +111,9 @@ protected:
 
     static const QString btnPreviewStr();
     static const QString btnSelectStr();
+
+private:
+    Gui::WeakPtrT<ViewProviderDressUp> DressUpView;
 };
 
 /// simulation dialog for the TaskView
diff --git a/src/Mod/PartDesign/Gui/TaskFilletParameters.cpp b/src/Mod/PartDesign/Gui/TaskFilletParameters.cpp
index 8e81ae18d3..cfe7175f71 100644
--- a/src/Mod/PartDesign/Gui/TaskFilletParameters.cpp
+++ b/src/Mod/PartDesign/Gui/TaskFilletParameters.cpp
@@ -115,13 +115,16 @@ void TaskFilletParameters::onSelectionChanged(const Gui::SelectionChanges& msg)
 
 void TaskFilletParameters::onCheckBoxUseAllEdgesToggled(bool checked)
 {
-    if (checked)
-        setSelectionMode(none);
-    PartDesign::Fillet* pcFillet = static_cast<PartDesign::Fillet*>(DressUpView->getObject());
-    ui->buttonRefSel->setEnabled(!checked);
-    ui->listWidgetReferences->setEnabled(!checked);
-    pcFillet->UseAllEdges.setValue(checked);
-    pcFillet->getDocument()->recomputeFeature(pcFillet);
+    if (auto fillet = getObject<PartDesign::Fillet>()) {
+        if (checked) {
+            setSelectionMode(none);
+        }
+
+        ui->buttonRefSel->setEnabled(!checked);
+        ui->listWidgetReferences->setEnabled(!checked);
+        fillet->UseAllEdges.setValue(checked);
+        fillet->recomputeFeature();
+    }
 }
 
 void TaskFilletParameters::setButtons(const selectionModes mode)
@@ -142,13 +145,14 @@ void TaskFilletParameters::onAddAllEdges()
 
 void TaskFilletParameters::onLengthChanged(double len)
 {
-    setSelectionMode(none);
-    PartDesign::Fillet* pcFillet = static_cast<PartDesign::Fillet*>(DressUpView->getObject());
-    setupTransaction();
-    pcFillet->Radius.setValue(len);
-    pcFillet->getDocument()->recomputeFeature(pcFillet);
-    // hide the fillet if there was a computation error
-    hideOnError();
+    if (auto fillet = getObject<PartDesign::Fillet>()) {
+        setSelectionMode(none);
+        setupTransaction();
+        fillet->Radius.setValue(len);
+        fillet->recomputeFeature();
+        // hide the fillet if there was a computation error
+        hideOnError();
+    }
 }
 
 double TaskFilletParameters::getLength() const
diff --git a/src/Mod/PartDesign/Gui/TaskThicknessParameters.cpp b/src/Mod/PartDesign/Gui/TaskThicknessParameters.cpp
index 05b974c5c3..31ccf74721 100644
--- a/src/Mod/PartDesign/Gui/TaskThicknessParameters.cpp
+++ b/src/Mod/PartDesign/Gui/TaskThicknessParameters.cpp
@@ -63,8 +63,8 @@ void TaskThicknessParameters::addContainerWidget()
 
 void TaskThicknessParameters::initControls()
 {
-    auto pcThickness = dynamic_cast<PartDesign::Thickness*>(DressUpView->getObject());
-    double a = pcThickness->Value.getValue();
+    auto thickness = getObject<PartDesign::Thickness>();
+    double a = thickness->Value.getValue();
 
     ui->Value->setMinimum(0.0);
     ui->Value->setValue(a);
@@ -72,25 +72,25 @@ void TaskThicknessParameters::initControls()
     QMetaObject::invokeMethod(ui->Value, "setFocus", Qt::QueuedConnection);
 
     // Bind input fields to properties
-    ui->Value->bind(pcThickness->Value);
+    ui->Value->bind(thickness->Value);
 
-    bool r = pcThickness->Reversed.getValue();
+    bool r = thickness->Reversed.getValue();
     ui->checkReverse->setChecked(r);
 
-    bool i = pcThickness->Intersection.getValue();
+    bool i = thickness->Intersection.getValue();
     ui->checkIntersection->setChecked(i);
 
-    std::vector<std::string> strings = pcThickness->Base.getSubValues();
+    std::vector<std::string> strings = thickness->Base.getSubValues();
     for (const auto& string : strings) {
         ui->listWidgetReferences->addItem(QString::fromStdString(string));
     }
 
     setupConnections();
 
-    int mode = static_cast<int>(pcThickness->Mode.getValue());
+    int mode = static_cast<int>(thickness->Mode.getValue());
     ui->modeComboBox->setCurrentIndex(mode);
 
-    int join = static_cast<int>(pcThickness->Join.getValue());
+    int join = static_cast<int>(thickness->Join.getValue());
     ui->joinComboBox->setCurrentIndex(join);
 
     if (strings.empty()) {
@@ -156,7 +156,7 @@ PartDesign::Thickness* TaskThicknessParameters::onBeforeChange()
 {
     setButtons(none);
     setupTransaction();
-    return dynamic_cast<PartDesign::Thickness*>(DressUpView->getObject());
+    return getObject<PartDesign::Thickness>();
 }
 
 void TaskThicknessParameters::onAfterChange(PartDesign::Thickness* obj)
@@ -168,25 +168,26 @@ void TaskThicknessParameters::onAfterChange(PartDesign::Thickness* obj)
 
 void TaskThicknessParameters::onValueChanged(double angle)
 {
-    PartDesign::Thickness* thickness = onBeforeChange();
-    thickness->Value.setValue(angle);
-    onAfterChange(thickness);
+    if (PartDesign::Thickness* thickness = onBeforeChange()) {
+        thickness->Value.setValue(angle);
+        onAfterChange(thickness);
+    }
 }
 
 void TaskThicknessParameters::onJoinTypeChanged(int join)
 {
-
-    PartDesign::Thickness* thickness = onBeforeChange();
-    thickness->Join.setValue(join);
-    onAfterChange(thickness);
+    if (PartDesign::Thickness* thickness = onBeforeChange()) {
+        thickness->Join.setValue(join);
+        onAfterChange(thickness);
+    }
 }
 
 void TaskThicknessParameters::onModeChanged(int mode)
 {
-
-    PartDesign::Thickness* thickness = onBeforeChange();
-    thickness->Mode.setValue(mode);
-    onAfterChange(thickness);
+    if (PartDesign::Thickness* thickness = onBeforeChange()) {
+        thickness->Mode.setValue(mode);
+        onAfterChange(thickness);
+    }
 }
 
 double TaskThicknessParameters::getValue() const
@@ -196,9 +197,10 @@ double TaskThicknessParameters::getValue() const
 
 void TaskThicknessParameters::onReversedChanged(bool on)
 {
-    PartDesign::Thickness* thickness = onBeforeChange();
-    thickness->Reversed.setValue(on);
-    onAfterChange(thickness);
+    if (PartDesign::Thickness* thickness = onBeforeChange()) {
+        thickness->Reversed.setValue(on);
+        onAfterChange(thickness);
+    }
 }
 
 bool TaskThicknessParameters::getReversed() const
@@ -208,9 +210,10 @@ bool TaskThicknessParameters::getReversed() const
 
 void TaskThicknessParameters::onIntersectionChanged(bool on)
 {
-    PartDesign::Thickness* thickness = onBeforeChange();
-    thickness->Intersection.setValue(on);
-    onAfterChange(thickness);
+    if (PartDesign::Thickness* thickness = onBeforeChange()) {
+        thickness->Intersection.setValue(on);
+        onAfterChange(thickness);
+    }
 }
 
 bool TaskThicknessParameters::getIntersection() const