diff --git a/src/Gui/CommandStd.cpp b/src/Gui/CommandStd.cpp
index d48a784e63..e8089ff289 100644
--- a/src/Gui/CommandStd.cpp
+++ b/src/Gui/CommandStd.cpp
@@ -343,7 +343,7 @@ void StdCmdRestartInSafeMode::activated(int iMsg)
 {
     Q_UNUSED(iMsg);
 
-    QMessageBox restartBox;
+    QMessageBox restartBox(Gui::getMainWindow());
     restartBox.setIcon(QMessageBox::Warning);
     restartBox.setWindowTitle(QObject::tr("Restart in safe mode"));
     restartBox.setText(QObject::tr("Are you sure you want to restart FreeCAD and enter safe mode?"));
diff --git a/src/Gui/Dialogs/DlgMacroExecuteImp.cpp b/src/Gui/Dialogs/DlgMacroExecuteImp.cpp
index eaa10d2270..24f793d5b8 100644
--- a/src/Gui/Dialogs/DlgMacroExecuteImp.cpp
+++ b/src/Gui/Dialogs/DlgMacroExecuteImp.cpp
@@ -565,7 +565,7 @@ void DlgMacroExecuteImp::onToolbarButtonClicked()
                          .GetParameterGroupByPath("User parameter:BaseApp/Preferences/Macro")
                          ->GetBool("ShowWalkthroughMessage", true);
     if (showAgain) {
-        QMessageBox msgBox;
+        QMessageBox msgBox(this);
         QAbstractButton* doNotShowAgainButton =
             msgBox.addButton(tr("Do not show again"), QMessageBox::YesRole);
         msgBox.setText(tr("Guided Walkthrough"));
diff --git a/src/Gui/Dialogs/DlgPreferencesImp.cpp b/src/Gui/Dialogs/DlgPreferencesImp.cpp
index 23d968e365..45b6656b94 100644
--- a/src/Gui/Dialogs/DlgPreferencesImp.cpp
+++ b/src/Gui/Dialogs/DlgPreferencesImp.cpp
@@ -759,7 +759,7 @@ void DlgPreferencesImp::applyChanges()
 void DlgPreferencesImp::restartIfRequired()
 {
     if (restartRequired) {
-        QMessageBox restartBox;
+        QMessageBox restartBox(parentWidget()); // current window likely already closed, cant parent to it
 
         restartBox.setIcon(QMessageBox::Warning);
         restartBox.setWindowTitle(tr("Restart required"));
diff --git a/src/Gui/Placement.cpp b/src/Gui/Placement.cpp
index 105d5e4174..0a2e1a7a01 100644
--- a/src/Gui/Placement.cpp
+++ b/src/Gui/Placement.cpp
@@ -708,7 +708,7 @@ void Placement::onSelectedVertexClicked()
 
     if (!success) {
         Base::Console().Warning("Placement selection error.  Select either 1 or 2 points.\n");
-        QMessageBox msgBox;
+        QMessageBox msgBox(this);
         msgBox.setText(tr("Please select 1, 2, or 3 points before clicking this button.  A point may be on a vertex, \
 face, or edge.  If on a face or edge the point used will be the point at the mouse position along \
 face or edge.  If 1 point is selected it will be used as the center of rotation.  If 2 points are \
diff --git a/src/Gui/TaskView/TaskDialog.cpp b/src/Gui/TaskView/TaskDialog.cpp
index 9c9e304f8c..5c5bceb088 100644
--- a/src/Gui/TaskView/TaskDialog.cpp
+++ b/src/Gui/TaskView/TaskDialog.cpp
@@ -30,6 +30,7 @@
 #include <App/Document.h>
 #include <Gui/Application.h>
 #include <Gui/Document.h>
+#include <Gui/MainWindow.h>
 #include <Gui/View3DInventor.h>
 #include <Gui/ViewProviderDocumentObject.h>
 
@@ -96,7 +97,7 @@ const std::vector<QWidget*> &TaskDialog::getDialogContent() const
 
 bool TaskDialog::canClose() const
 {
-    QMessageBox msgBox;
+    QMessageBox msgBox(Gui::getMainWindow());
     msgBox.setText(tr("A dialog is already open in the task panel"));
     msgBox.setInformativeText(QObject::tr("Do you want to close this dialog?"));
     msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
diff --git a/src/Mod/Assembly/Gui/ViewProviderAssembly.cpp b/src/Mod/Assembly/Gui/ViewProviderAssembly.cpp
index b9a59e29a0..605bd6bfba 100644
--- a/src/Mod/Assembly/Gui/ViewProviderAssembly.cpp
+++ b/src/Mod/Assembly/Gui/ViewProviderAssembly.cpp
@@ -55,6 +55,7 @@
 #include <Gui/CommandT.h>
 #include <Gui/Control.h>
 #include <Gui/MDIView.h>
+#include <Gui/MainWindow.h>
 #include <Gui/SoFCCSysDragger.h>
 #include <Gui/View3DInventor.h>
 #include <Gui/View3DInventorViewer.h>
@@ -191,7 +192,7 @@ bool ViewProviderAssembly::canDragObjectToTarget(App::DocumentObject* obj,
         if (obj == obj1 || obj == obj2 || obj == part1 || obj == part2 || obj == obj3) {
             if (!prompted) {
                 prompted = true;
-                QMessageBox msgBox;
+                QMessageBox msgBox(Gui::getMainWindow());
                 msgBox.setText(tr("The object is associated to one or more joints."));
                 msgBox.setInformativeText(
                     tr("Do you want to move the object and delete associated joints?"));
diff --git a/src/Mod/Fem/Gui/ViewProviderFemPostFunction.cpp b/src/Mod/Fem/Gui/ViewProviderFemPostFunction.cpp
index 15b3832b7a..866a64d3dc 100644
--- a/src/Mod/Fem/Gui/ViewProviderFemPostFunction.cpp
+++ b/src/Mod/Fem/Gui/ViewProviderFemPostFunction.cpp
@@ -333,7 +333,7 @@ bool ViewProviderFemPostFunction::setEdit(int ModNum)
             postDlg = nullptr;  // another pad left open its task panel
         }
         if (dlg && !postDlg) {
-            QMessageBox msgBox;
+            QMessageBox msgBox(Gui::getMainWindow());
             msgBox.setText(QObject::tr("A dialog is already open in the task panel"));
             msgBox.setInformativeText(QObject::tr("Do you want to close this dialog?"));
             msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
diff --git a/src/Mod/Fem/Gui/ViewProviderFemPostObject.cpp b/src/Mod/Fem/Gui/ViewProviderFemPostObject.cpp
index 32b68bf036..a943d1c0ed 100644
--- a/src/Mod/Fem/Gui/ViewProviderFemPostObject.cpp
+++ b/src/Mod/Fem/Gui/ViewProviderFemPostObject.cpp
@@ -964,7 +964,7 @@ bool ViewProviderFemPostObject::setEdit(int ModNum)
             postDlg = nullptr;  // another pad left open its task panel
         }
         if (dlg && !postDlg) {
-            QMessageBox msgBox;
+            QMessageBox msgBox(Gui::getMainWindow());
             msgBox.setText(QObject::tr("A dialog is already open in the task panel"));
             msgBox.setInformativeText(QObject::tr("Do you want to close this dialog?"));
             msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
diff --git a/src/Mod/PartDesign/Gui/Command.cpp b/src/Mod/PartDesign/Gui/Command.cpp
index 3aa89d77c6..9ccbebe3f9 100644
--- a/src/Mod/PartDesign/Gui/Command.cpp
+++ b/src/Mod/PartDesign/Gui/Command.cpp
@@ -890,7 +890,7 @@ void prepareProfileBased(PartDesign::Body *pcActiveBody, Gui::Command* cmd, cons
         (which.compare("Pocket") == 0)) {
 
         if (!pcActiveBody->isSolid()) {
-            QMessageBox msgBox;
+            QMessageBox msgBox(Gui::getMainWindow());
             msgBox.setText(QObject::tr("Cannot use this command as there is no solid to subtract from."));
             msgBox.setInformativeText(QObject::tr("Ensure that the body contains a feature before attempting a subtractive command."));
             msgBox.setStandardButtons(QMessageBox::Ok);
@@ -912,7 +912,7 @@ void prepareProfileBased(PartDesign::Body *pcActiveBody, Gui::Command* cmd, cons
             }
         }
         if (!onlyAllowed) {
-            QMessageBox msgBox;
+            QMessageBox msgBox(Gui::getMainWindow());
             msgBox.setText(QObject::tr("Cannot use selected object. Selected object must belong to the active body"));
             msgBox.setInformativeText(QObject::tr("Consider using a ShapeBinder or a BaseFeature to reference external geometry in a body."));
             msgBox.setStandardButtons(QMessageBox::Ok);
@@ -1010,7 +1010,7 @@ void prepareProfileBased(PartDesign::Body *pcActiveBody, Gui::Command* cmd, cons
         Gui::TaskView::TaskDialog *dlg = Gui::Control().activeDialog();
         PartDesignGui::TaskDlgFeaturePick *pickDlg = qobject_cast<PartDesignGui::TaskDlgFeaturePick *>(dlg);
         if (dlg && !pickDlg) {
-            QMessageBox msgBox;
+            QMessageBox msgBox(Gui::getMainWindow());
             msgBox.setText(QObject::tr("A dialog is already open in the task panel"));
             msgBox.setInformativeText(QObject::tr("Do you want to close this dialog?"));
             msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
diff --git a/src/Mod/PartDesign/Gui/SketchWorkflow.cpp b/src/Mod/PartDesign/Gui/SketchWorkflow.cpp
index 7cff72aa52..945bdc5126 100644
--- a/src/Mod/PartDesign/Gui/SketchWorkflow.cpp
+++ b/src/Mod/PartDesign/Gui/SketchWorkflow.cpp
@@ -651,7 +651,7 @@ private:
         Gui::TaskView::TaskDialog *dlg = Gui::Control().activeDialog();
         PartDesignGui::TaskDlgFeaturePick *pickDlg = qobject_cast<PartDesignGui::TaskDlgFeaturePick *>(dlg);
         if (dlg && !pickDlg) {
-            QMessageBox msgBox;
+            QMessageBox msgBox(Gui::getMainWindow());
             msgBox.setText(QObject::tr("A dialog is already open in the task panel"));
             msgBox.setInformativeText(QObject::tr("Do you want to close this dialog?"));
             msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
diff --git a/src/Mod/PartDesign/Gui/TaskDatumParameters.cpp b/src/Mod/PartDesign/Gui/TaskDatumParameters.cpp
index be800cd17d..47839dc795 100644
--- a/src/Mod/PartDesign/Gui/TaskDatumParameters.cpp
+++ b/src/Mod/PartDesign/Gui/TaskDatumParameters.cpp
@@ -97,7 +97,7 @@ bool TaskDlgDatumParameters::accept() {
 
     //see if we are able to assign a mode
     if (parameter->getActiveMapMode() == mmDeactivated) {
-        QMessageBox msg;
+        QMessageBox msg(Gui::getMainWindow());
         msg.setWindowTitle(tr("Incompatible reference set"));
         msg.setText(tr("There is no attachment mode that fits the current set"
         " of references. If you choose to continue, the feature will remain where"
diff --git a/src/Mod/PartDesign/Gui/ViewProvider.cpp b/src/Mod/PartDesign/Gui/ViewProvider.cpp
index fe48ac3787..512b87c62a 100644
--- a/src/Mod/PartDesign/Gui/ViewProvider.cpp
+++ b/src/Mod/PartDesign/Gui/ViewProvider.cpp
@@ -37,6 +37,7 @@
 #include <Gui/Command.h>
 #include <Gui/Control.h>
 #include <Gui/Document.h>
+#include <Gui/MainWindow.h>
 #include <Mod/PartDesign/App/Body.h>
 #include <Mod/PartDesign/App/Feature.h>
 
@@ -101,7 +102,7 @@ bool ViewProvider::setEdit(int ModNum)
             featureDlg = nullptr; // another feature left open its task panel
         }
         if (dlg && !featureDlg) {
-            QMessageBox msgBox;
+            QMessageBox msgBox(Gui::getMainWindow());
             msgBox.setText(QObject::tr("A dialog is already open in the task panel"));
             msgBox.setInformativeText(QObject::tr("Do you want to close this dialog?"));
             msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
diff --git a/src/Mod/PartDesign/Gui/ViewProviderBoolean.cpp b/src/Mod/PartDesign/Gui/ViewProviderBoolean.cpp
index 7751e4c438..0bafeccfec 100644
--- a/src/Mod/PartDesign/Gui/ViewProviderBoolean.cpp
+++ b/src/Mod/PartDesign/Gui/ViewProviderBoolean.cpp
@@ -36,6 +36,7 @@
 #include <Gui/Control.h>
 #include <Gui/Command.h>
 #include <Gui/Document.h>
+#include <Gui/MainWindow.h>
 
 
 using namespace PartDesignGui;
@@ -74,7 +75,7 @@ bool ViewProviderBoolean::setEdit(int ModNum)
         if (booleanDlg && booleanDlg->getBooleanView() != this)
             booleanDlg = nullptr; // another pad left open its task panel
         if (dlg && !booleanDlg) {
-            QMessageBox msgBox;
+            QMessageBox msgBox(Gui::getMainWindow());
             msgBox.setText(QObject::tr("A dialog is already open in the task panel"));
             msgBox.setInformativeText(QObject::tr("Do you want to close this dialog?"));
             msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
diff --git a/src/Mod/PartDesign/Gui/ViewProviderDatum.cpp b/src/Mod/PartDesign/Gui/ViewProviderDatum.cpp
index 433935a5a5..474dc3b9d0 100644
--- a/src/Mod/PartDesign/Gui/ViewProviderDatum.cpp
+++ b/src/Mod/PartDesign/Gui/ViewProviderDatum.cpp
@@ -45,6 +45,7 @@
 #include <Gui/Application.h>
 #include <Gui/Command.h>
 #include <Gui/Control.h>
+#include <Gui/MainWindow.h>
 #include <Gui/View3DInventor.h>
 #include <Gui/View3DInventorViewer.h>
 #include <Gui/ViewProviderCoordinateSystem.h>
@@ -245,7 +246,7 @@ bool ViewProviderDatum::setEdit(int ModNum)
         if (datumDlg && datumDlg->getViewProvider() != this)
             datumDlg = nullptr; // another datum feature left open its task panel
         if (dlg && !datumDlg) {
-            QMessageBox msgBox;
+            QMessageBox msgBox(Gui::getMainWindow());
             msgBox.setText(QObject::tr("A dialog is already open in the task panel"));
             msgBox.setInformativeText(QObject::tr("Do you want to close this dialog?"));
             msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
diff --git a/src/Mod/PartDesign/Gui/ViewProviderHole.cpp b/src/Mod/PartDesign/Gui/ViewProviderHole.cpp
index 0b8d1bd9fc..9a1d48418e 100644
--- a/src/Mod/PartDesign/Gui/ViewProviderHole.cpp
+++ b/src/Mod/PartDesign/Gui/ViewProviderHole.cpp
@@ -31,6 +31,7 @@
 #include <Gui/Application.h>
 #include <Gui/Control.h>
 #include <Gui/Command.h>
+#include <Gui/MainWindow.h>
 #include <Mod/PartDesign/App/FeatureHole.h>
 #include <Mod/Sketcher/App/SketchObject.h>
 
@@ -73,7 +74,7 @@ bool ViewProviderHole::setEdit(int ModNum)
         if (holeDlg && holeDlg->getViewObject() != this)
             holeDlg = nullptr; // another hole left open its task panel
         if (dlg && !holeDlg) {
-            QMessageBox msgBox;
+            QMessageBox msgBox(Gui::getMainWindow());
             msgBox.setText(QObject::tr("A dialog is already open in the task panel"));
             msgBox.setInformativeText(QObject::tr("Do you want to close this dialog?"));
             msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
diff --git a/src/Mod/PartDesign/Gui/ViewProviderPrimitive.cpp b/src/Mod/PartDesign/Gui/ViewProviderPrimitive.cpp
index 5c40f56676..2549e299b8 100644
--- a/src/Mod/PartDesign/Gui/ViewProviderPrimitive.cpp
+++ b/src/Mod/PartDesign/Gui/ViewProviderPrimitive.cpp
@@ -30,6 +30,7 @@
 #include <Gui/BitmapFactory.h>
 #include <Gui/Command.h>
 #include <Gui/Control.h>
+#include <Gui/MainWindow.h>
 #include <Gui/TaskView/TaskDialog.h>
 #include <Mod/PartDesign/App/FeaturePrimitive.h>
 
@@ -64,7 +65,7 @@ bool ViewProviderPrimitive::setEdit(int ModNum)
         Gui::TaskView::TaskDialog *dlg = Gui::Control().activeDialog();
         TaskPrimitiveParameters *primitiveDlg = qobject_cast<TaskPrimitiveParameters *>(dlg);
         if (dlg && !primitiveDlg) {
-            QMessageBox msgBox;
+            QMessageBox msgBox(Gui::getMainWindow());
             msgBox.setText(QObject::tr("A dialog is already open in the task panel"));
             msgBox.setInformativeText(QObject::tr("Do you want to close this dialog?"));
             msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
diff --git a/src/Mod/PartDesign/Gui/ViewProviderShapeBinder.cpp b/src/Mod/PartDesign/Gui/ViewProviderShapeBinder.cpp
index ee07d3b742..7c54e1003b 100644
--- a/src/Mod/PartDesign/Gui/ViewProviderShapeBinder.cpp
+++ b/src/Mod/PartDesign/Gui/ViewProviderShapeBinder.cpp
@@ -38,6 +38,7 @@
 #include <Gui/Command.h>
 #include <Gui/Control.h>
 #include <Gui/Document.h>
+#include <Gui/MainWindow.h>
 #include <Gui/ViewParams.h>
 #include <Mod/PartDesign/App/ShapeBinder.h>
 
@@ -91,7 +92,7 @@ bool ViewProviderShapeBinder::setEdit(int ModNum) {
         Gui::TaskView::TaskDialog* dlg = Gui::Control().activeDialog();
         TaskDlgShapeBinder* sbDlg = qobject_cast<TaskDlgShapeBinder*>(dlg);
         if (dlg && !sbDlg) {
-            QMessageBox msgBox;
+            QMessageBox msgBox(Gui::getMainWindow());
             msgBox.setText(QObject::tr("A dialog is already open in the task panel"));
             msgBox.setInformativeText(QObject::tr("Do you want to close this dialog?"));
             msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
diff --git a/src/Mod/Points/Gui/Command.cpp b/src/Mod/Points/Gui/Command.cpp
index b08d6ea61b..b0f76cb089 100644
--- a/src/Mod/Points/Gui/Command.cpp
+++ b/src/Mod/Points/Gui/Command.cpp
@@ -112,7 +112,7 @@ void CmdPointsImport::activated(int iMsg)
             auto center = bbox.GetCenter();
 
             if (!bbox.IsInBox(Base::Vector3d(0, 0, 0))) {
-                QMessageBox msgBox;
+                QMessageBox msgBox(Gui::getMainWindow());
                 msgBox.setIcon(QMessageBox::Question);
                 msgBox.setWindowTitle(QObject::tr("Points not at Origin"));
                 msgBox.setText(QObject::tr(
diff --git a/src/Mod/Sketcher/Gui/ViewProviderSketch.cpp b/src/Mod/Sketcher/Gui/ViewProviderSketch.cpp
index 781a939522..613b045447 100644
--- a/src/Mod/Sketcher/Gui/ViewProviderSketch.cpp
+++ b/src/Mod/Sketcher/Gui/ViewProviderSketch.cpp
@@ -2980,7 +2980,7 @@ bool ViewProviderSketch::setEdit(int ModNum)
     if (sketchDlg && sketchDlg->getSketchView() != this)
         sketchDlg = nullptr;// another sketch left open its task panel
     if (dlg && !sketchDlg) {
-        QMessageBox msgBox;
+        QMessageBox msgBox(Gui::getMainWindow());
         msgBox.setText(tr("A dialog is already open in the task panel"));
         msgBox.setInformativeText(tr("Do you want to close this dialog?"));
         msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
diff --git a/src/Mod/TechDraw/Gui/Command.cpp b/src/Mod/TechDraw/Gui/Command.cpp
index 3dc13cbcb7..321788f54d 100644
--- a/src/Mod/TechDraw/Gui/Command.cpp
+++ b/src/Mod/TechDraw/Gui/Command.cpp
@@ -424,7 +424,7 @@ void CmdTechDrawView::activated(int iMsg)
             bool dontShowAgain = hGrp->GetBool("DontShowInsertFileMessage", false);
             if (!dontShowAgain) {
                 auto msgText = QObject::tr("If you want to insert a view from existing objects, please select them before invoking this tool. Without a selection, a file browser will open, to insert a SVG or image file.");
-                QMessageBox msgBox;
+                QMessageBox msgBox(Gui::getMainWindow());
                 msgBox.setText(msgText);
                 auto dontShowMsg = QObject::tr("Do not show this message again");
                 QCheckBox dontShowCheckBox(dontShowMsg, &msgBox);
diff --git a/src/Mod/TechDraw/Gui/CommandExtensionDims.cpp b/src/Mod/TechDraw/Gui/CommandExtensionDims.cpp
index 42bc104862..64d16ae320 100644
--- a/src/Mod/TechDraw/Gui/CommandExtensionDims.cpp
+++ b/src/Mod/TechDraw/Gui/CommandExtensionDims.cpp
@@ -113,7 +113,7 @@ void execInsertPrefixChar(Gui::Command* cmd, std::string prefixFormat, const QAc
 
     std::string prefixText(prefixFormat);
     if (prefixFormat.find("%s") != std::string::npos) {
-        DlgTemplateField ui;
+        DlgTemplateField ui(Gui::getMainWindow());
         const int MAX_PREFIX_LENGTH = 31;
 
         if (action) {
diff --git a/src/Mod/TechDraw/Gui/TemplateTextField.cpp b/src/Mod/TechDraw/Gui/TemplateTextField.cpp
index dd22a49863..f8afce0f33 100644
--- a/src/Mod/TechDraw/Gui/TemplateTextField.cpp
+++ b/src/Mod/TechDraw/Gui/TemplateTextField.cpp
@@ -30,6 +30,7 @@
 #endif // #ifndef _PreCmp_
 
 #include <Base/Console.h>
+#include <Gui/MainWindow.h>
 
 #include <Mod/TechDraw/App/DrawTemplate.h>
 #include <Mod/TechDraw/App/DrawSVGTemplate.h>
@@ -73,7 +74,7 @@ void TemplateTextField::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
     if ( tmplte && m_rect->rect().contains(event->pos()) ) {
         event->accept();
 
-        DlgTemplateField ui;
+        DlgTemplateField ui(Gui::getMainWindow());
 
         ui.setFieldName(fieldNameStr);
         ui.setFieldContent(tmplte->EditableTexts[fieldNameStr]);