diff --git a/sources/editor/ui/qetelementeditor.cpp b/sources/editor/ui/qetelementeditor.cpp
index 8a5df0ee2..28712d4ac 100644
--- a/sources/editor/ui/qetelementeditor.cpp
+++ b/sources/editor/ui/qetelementeditor.cpp
@@ -78,8 +78,9 @@ QETElementEditor::QETElementEditor(QWidget *parent) :
 	//ui->m_display_menu->insertMenu(ui->m_zoom_in_action, menu);
 
 	setWindowState(Qt::WindowMaximized);
-	readSettings();
+	readSettings();  // restoreGeometry before show()
 	show();
+	readSettingsState();  // restoreState() must be called after show() in Qt6
 }
 
 /**
@@ -951,16 +952,28 @@ void QETElementEditor::readSettings()
 		restoreGeometry(geometry.toByteArray());
 	}
 
-	QVariant state = settings.value("elementeditor/state");
-	if (state.isValid()) {
-		restoreState(state.toByteArray());
-	}
-
 	auto data = m_elmt_scene->elementData();
 	data.m_drawing_information = settings.value("elementeditor/default-informations", "").toString();
 	m_elmt_scene->setElementData(data);
 }
 
+/**
+ * @brief QETElementEditor::readSettingsState
+ * Restore the window state (docks, toolbars).
+ * Must be called AFTER show() in Qt6 for restoreState() to work correctly.
+ */
+void QETElementEditor::readSettingsState()
+{
+	QSettings settings;
+
+	QVariant state = settings.value("elementeditor/state");
+	if (state.isValid()) {
+		if (!restoreState(state.toByteArray())) {
+			settings.remove("elementeditor/state");
+		}
+	}
+}
+
 /**
  * @brief QETElementEditor::writeSettings
  * Write some setting of this widget in the
diff --git a/sources/editor/ui/qetelementeditor.h b/sources/editor/ui/qetelementeditor.h
index 579d9bab4..b164017f8 100644
--- a/sources/editor/ui/qetelementeditor.h
+++ b/sources/editor/ui/qetelementeditor.h
@@ -116,6 +116,7 @@ class QETElementEditor : public QMainWindow
 	private:
 		bool canClose();
 		void readSettings();
+		void readSettingsState();
 		void writeSettings() const;
 		void setupActions();
 		void updateAction();
diff --git a/sources/qetapp.cpp b/sources/qetapp.cpp
index d8afcc34b..0463be2ee 100644
--- a/sources/qetapp.cpp
+++ b/sources/qetapp.cpp
@@ -1975,6 +1975,7 @@ void QETApp::openTitleBlockTemplate(const TitleBlockTemplateLocation &location,
 	qet_template_editor -> setOpenForDuplication(duplicate);
 	qet_template_editor -> edit(location);
 	qet_template_editor -> show();
+	qet_template_editor -> readSettingsState();  // must run after show() in Qt6
 }
 
 /**
@@ -1986,6 +1987,7 @@ void QETApp::openTitleBlockTemplate(const QString &filepath) {
 	QETTitleBlockTemplateEditor *qet_template_editor = new QETTitleBlockTemplateEditor();
 	qet_template_editor -> edit(filepath);
 	qet_template_editor -> show();
+	qet_template_editor -> readSettingsState();  // must run after show() in Qt6
 }
 
 /**
diff --git a/sources/qetdiagrameditor.cpp b/sources/qetdiagrameditor.cpp
index 6e5e5d1d6..a17412a72 100644
--- a/sources/qetdiagrameditor.cpp
+++ b/sources/qetdiagrameditor.cpp
@@ -135,8 +135,9 @@ QETDiagramEditor::QETDiagramEditor(const QStringList &files, QWidget *parent) :
 	connect(&m_workspace, &QMdiArea::subWindowActivated, this, &QETDiagramEditor::subWindowActivated);
 	connect(QApplication::clipboard(), &QClipboard::dataChanged, this, &QETDiagramEditor::slot_updatePasteAction);
 
-	readSettings();
+	readSettings();  // restoreGeometry before show()
 	show();
+	readSettingsState();  // restoreState() must be called after show() in Qt6
 
 		//If valid file path is given as arguments
 	uint opened_projects = 0;
@@ -2227,10 +2228,6 @@ void QETDiagramEditor::readSettings()
 	QVariant geometry = settings.value("diagrameditor/geometry");
 	if (geometry.isValid()) restoreGeometry(geometry.toByteArray());
 
-	// etat de la fenetre (barres d'outils, docks...)
-	QVariant state = settings.value("diagrameditor/state");
-	if (state.isValid()) restoreState(state.toByteArray());
-
 	// gestion des projets (onglets ou fenetres)
 	bool tabbed = settings.value("diagrameditor/viewmode", "tabbed") == "tabbed";
 	if (tabbed) {
@@ -2240,6 +2237,24 @@ void QETDiagramEditor::readSettings()
 	}
 }
 
+/**
+	@brief QETDiagramEditor::readSettingsState
+	Restore the window state (docks, toolbars).
+	Must be called AFTER show() in Qt6 for restoreState() to work correctly.
+*/
+void QETDiagramEditor::readSettingsState()
+{
+	QSettings settings;
+
+	// etat de la fenetre (barres d'outils, docks...)
+	QVariant state = settings.value("diagrameditor/state");
+	if (state.isValid()) {
+		if (!restoreState(state.toByteArray())) {
+			settings.remove("diagrameditor/state");
+		}
+	}
+}
+
 /**
 	@brief QETDiagramEditor::writeSettings
 	Write the settings
diff --git a/sources/qetdiagrameditor.h b/sources/qetdiagrameditor.h
index a1b08c037..31e6ce82c 100644
--- a/sources/qetdiagrameditor.h
+++ b/sources/qetdiagrameditor.h
@@ -127,6 +127,7 @@ class QETDiagramEditor : public QETMainWindow
 		void setWindowedMode();
 		void setTabbedMode();
 		void readSettings();
+		void readSettingsState();
 		void writeSettings();
 		void activateProject(QETProject *);
 		void activateProject(ProjectView *);
diff --git a/sources/titleblock/qettemplateeditor.cpp b/sources/titleblock/qettemplateeditor.cpp
index 3a316f15b..e3a44ecbb 100644
--- a/sources/titleblock/qettemplateeditor.cpp
+++ b/sources/titleblock/qettemplateeditor.cpp
@@ -358,6 +358,7 @@ void QETTitleBlockTemplateEditor::newTemplate()
 	QETTitleBlockTemplateEditor *qet_template_editor = new QETTitleBlockTemplateEditor();
 	qet_template_editor -> edit(TitleBlockTemplateLocation());
 	qet_template_editor -> show();
+	qet_template_editor -> readSettingsState();  // must run after show() in Qt6
 }
 
 /**
@@ -645,10 +646,25 @@ void QETTitleBlockTemplateEditor::readSettings()
 	// window size and position
 	QVariant geometry = settings.value("titleblocktemplateeditor/geometry");
 	if (geometry.isValid()) restoreGeometry(geometry.toByteArray());
+}
+
+/**
+	@brief QETTitleBlockTemplateEditor::readSettingsState
+	Restore the window state (docks, toolbars).
+	Must be called AFTER show() in Qt6 for restoreState() to work correctly
+	-- callers are responsible for calling this after show(), since this
+	window isn't shown by its own constructor.
+*/
+void QETTitleBlockTemplateEditor::readSettingsState()
+{
+	QSettings settings;
 
-	// window state (toolbars, docks...)
 	QVariant state = settings.value("titleblocktemplateeditor/state");
-	if (state.isValid()) restoreState(state.toByteArray());
+	if (state.isValid()) {
+		if (!restoreState(state.toByteArray())) {
+			settings.remove("titleblocktemplateeditor/state");
+		}
+	}
 }
 
 /**
diff --git a/sources/titleblock/qettemplateeditor.h b/sources/titleblock/qettemplateeditor.h
index 67ac3c231..cfb6709b7 100644
--- a/sources/titleblock/qettemplateeditor.h
+++ b/sources/titleblock/qettemplateeditor.h
@@ -108,6 +108,7 @@ class QETTitleBlockTemplateEditor : public QETMainWindow {
 
 	public slots:
 	void readSettings();
+	void readSettingsState();
 	void writeSettings();
 	void selectedCellsChanged(const QList<TitleBlockCell *>&);
 	void duplicateCurrentLocation();