diff --git a/sources/configpages.cpp b/sources/configpages.cpp
index 5f9cf6c09..4d5849909 100644
--- a/sources/configpages.cpp
+++ b/sources/configpages.cpp
@@ -114,7 +114,6 @@ void NewDiagramPage::applyConf() {
 		if (m_project -> defaultTitleBlockProperties() != new_tbt_prop) {
 			m_project -> setDefaultTitleBlockProperties(ipw -> properties());
 			modified_project = true;
-			emit (m_project->defaultTitleBlockPropertiesChanged());
 		}
 
 		ConductorProperties new_conductor_prop = cpw -> properties();
diff --git a/sources/projectview.cpp b/sources/projectview.cpp
index d4c7bc151..a79fca98a 100644
--- a/sources/projectview.cpp
+++ b/sources/projectview.cpp
@@ -116,10 +116,13 @@ QList<Diagram *> ProjectView::getDiagrams(ProjectSaveOptions options) {
 }
 
 /**
-	@return le schema actuellement active
-*/
+ * @brief ProjectView::currentDiagram
+ * @return The current active diagram view or nullptr if there isn't diagramView in this project view.
+ */
 DiagramView *ProjectView::currentDiagram() const {
 	int current_tab_index = m_tab -> currentIndex();
+	if (current_tab_index == -1)
+		return nullptr;
 	return(diagram_ids_[current_tab_index]);
 }
 
diff --git a/sources/ui/autonumberingdockwidget.cpp b/sources/ui/autonumberingdockwidget.cpp
index b96b46158..e10b2e4e1 100644
--- a/sources/ui/autonumberingdockwidget.cpp
+++ b/sources/ui/autonumberingdockwidget.cpp
@@ -145,19 +145,20 @@ void AutoNumberingDockWidget::setConductorActive(DiagramView* dv) {
 void AutoNumberingDockWidget::setActive() {
 
 	if (projectview_!=NULL) {
-		//Conductor
-		QString conductor_autonum = projectview_->currentDiagram()->diagram()->conductorsAutonumName();
-		int conductor_index = ui->m_conductor_cb->findText(conductor_autonum);
-		ui->m_conductor_cb->setCurrentIndex(conductor_index);
+			//Conductor
+		if (projectview_->currentDiagram()) {
+			QString conductor_autonum = projectview_->currentDiagram()->diagram()->conductorsAutonumName();
+			int conductor_index = ui->m_conductor_cb->findText(conductor_autonum);
+			ui->m_conductor_cb->setCurrentIndex(conductor_index);
+		}
 
-		//Element
-		QString current_element_autonum = project_->elementCurrentAutoNum();
+			//Element
 		QString element_formula = project_->elementAutoNumFormula();
 		QString active_element_autonum = project_->elementAutoNumHash().key(element_formula);
 		int el_index = ui->m_element_cb->findText(active_element_autonum);
 		ui->m_element_cb->setCurrentIndex(el_index);
 
-		//Folio
+			//Folio
 		if (project_->defaultTitleBlockProperties().folio == "%autonum") {
 			QString page_autonum = project_->defaultTitleBlockProperties().auto_page_num;
 			int folio_index = ui->m_folio_cb->findText(page_autonum);