diff --git a/sources/TerminalStrip/ui/terminalstripeditorwindow.cpp b/sources/TerminalStrip/ui/terminalstripeditorwindow.cpp
index c47660bd9..aee833db9 100644
--- a/sources/TerminalStrip/ui/terminalstripeditorwindow.cpp
+++ b/sources/TerminalStrip/ui/terminalstripeditorwindow.cpp
@@ -29,8 +29,48 @@
 #include "terminalstripeditorwindow.h"
 #include "terminalstriptreedockwidget.h"
 
+#include <QApplication>
+#include <QProgressDialog>
+
 QPointer<TerminalStripEditorWindow> TerminalStripEditorWindow::window_;
 
+/**
+ * @brief TerminalStripEditorWindow::instance
+ * @param project : the project to edit
+ * @param parent : parent widget of the window, when it is created
+ * @return the terminal block manager window, created the first time,
+ * showing the terminal strips of @a project.
+ * Opening it reads every terminal of the project (and builds the folios
+ * not built yet) : it can take a while on a big project. A message and a
+ * busy cursor say that it is opening, so that the user does not think
+ * that nothing happens.
+ */
+TerminalStripEditorWindow *TerminalStripEditorWindow::instance(QETProject *project, QWidget *parent)
+{
+	QProgressDialog busy_(tr("Opening the terminal block manager..."), QString(), 0, 0, parent);
+	busy_.setWindowTitle(tr("Terminal block manager"));
+	busy_.setWindowModality(Qt::ApplicationModal);
+	busy_.setCancelButton(nullptr);
+	busy_.setMinimumDuration(0);
+	busy_.show();
+		//Paint the message before the long work starts
+	QCoreApplication::processEvents(QEventLoop::ExcludeUserInputEvents);
+	QApplication::setOverrideCursor(Qt::WaitCursor);
+
+	static QMutex mutex_;
+	if (!window_) {
+		mutex_.lock();
+		if (!window_)
+			window_ = new TerminalStripEditorWindow{project, parent};
+		mutex_.unlock();
+	} else {
+		window_->setProject(project);
+	}
+
+	QApplication::restoreOverrideCursor();
+	return window_;
+}
+
 static const int EMPTY_PAGE = 0;
 static const int FREE_TERMINAL_PAGE = 1;
 static const int TERMINAL_STRIP_PAGE = 2;
diff --git a/sources/TerminalStrip/ui/terminalstripeditorwindow.h b/sources/TerminalStrip/ui/terminalstripeditorwindow.h
index 10c41f468..8786104dc 100644
--- a/sources/TerminalStrip/ui/terminalstripeditorwindow.h
+++ b/sources/TerminalStrip/ui/terminalstripeditorwindow.h
@@ -44,18 +44,7 @@ class TerminalStripEditorWindow : public QMainWindow
 		static QPointer<TerminalStripEditorWindow> window_;
 
     public:
-        static TerminalStripEditorWindow* instance(QETProject *project, QWidget *parent = nullptr) {
-            static QMutex mutex_;
-            if (!window_) {
-                mutex_.lock();
-                if (!window_)
-                    window_ = new TerminalStripEditorWindow{project, parent};
-                mutex_.unlock();
-            } else {
-                window_->setProject(project);
-            }
-            return window_;
-        }
+		static TerminalStripEditorWindow* instance(QETProject *project, QWidget *parent = nullptr);
 
 		static void dropInstance () {
 			static QMutex mutex;