Index: Core/Gui/src/Core.Gui/Forms/Main/MainWindow.xaml.cs
===================================================================
diff -u -re093037094e59f25c0877167cd63287baf2f8409 -rbbb6068d01161dfc28efeb537d9c4ff324c373b8
--- Core/Gui/src/Core.Gui/Forms/Main/MainWindow.xaml.cs	(.../MainWindow.xaml.cs)	(revision e093037094e59f25c0877167cd63287baf2f8409)
+++ Core/Gui/src/Core.Gui/Forms/Main/MainWindow.xaml.cs	(.../MainWindow.xaml.cs)	(revision bbb6068d01161dfc28efeb537d9c4ff324c373b8)
@@ -561,11 +561,10 @@
             {
                 propertyGrid = new PropertyGridView(gui.PropertyResolver)
                 {
-                    Text = Properties.Resources.Properties_DisplayName,
                     Data = applicationSelection.Selection
                 };
 
-                viewController.ViewHost.AddToolView(propertyGrid, ToolViewLocation.Right, "\uE905");
+                viewController.ViewHost.AddToolView(propertyGrid, ToolViewLocation.Right, Properties.Resources.Properties_DisplayName, "\uE905");
             }
             else
             {
@@ -607,11 +606,9 @@
 
         private void InitMessagesWindow()
         {
-            MessageWindow = new MessageWindow(this)
-            {
-                Text = Properties.Resources.Messages
-            };
-            viewController.ViewHost.AddToolView(MessageWindow, ToolViewLocation.Bottom, "\uE906");
+            MessageWindow = new MessageWindow(this);
+
+            viewController.ViewHost.AddToolView(MessageWindow, ToolViewLocation.Bottom, Properties.Resources.Messages, "\uE906");
         }
 
         private void InitMapLegendWindow()
Index: Core/Gui/test/Core.Gui.Test/Forms/ViewHost/AvalonDockViewHostTest.cs
===================================================================
diff -u -r0c2079726458d902cc7b2424907383bfc68ba111 -rbbb6068d01161dfc28efeb537d9c4ff324c373b8
--- Core/Gui/test/Core.Gui.Test/Forms/ViewHost/AvalonDockViewHostTest.cs	(.../AvalonDockViewHostTest.cs)	(revision 0c2079726458d902cc7b2424907383bfc68ba111)
+++ Core/Gui/test/Core.Gui.Test/Forms/ViewHost/AvalonDockViewHostTest.cs	(.../AvalonDockViewHostTest.cs)	(revision bbb6068d01161dfc28efeb537d9c4ff324c373b8)
@@ -72,8 +72,8 @@
 
             avalonDockViewHost.AddDocumentView(testView1, string.Empty);
             avalonDockViewHost.AddDocumentView(testView2, string.Empty);
-            avalonDockViewHost.AddToolView(testView3, ToolViewLocation.Left, string.Empty);
-            avalonDockViewHost.AddToolView(testView4, ToolViewLocation.Left, string.Empty);
+            avalonDockViewHost.AddToolView(testView3, ToolViewLocation.Left, string.Empty, string.Empty);
+            avalonDockViewHost.AddToolView(testView4, ToolViewLocation.Left, string.Empty, string.Empty);
 
             SetActiveView(avalonDockViewHost, testView1);
 
@@ -279,7 +279,7 @@
             using (var avalonDockViewHost = new AvalonDockViewHost())
             {
                 avalonDockViewHost.AddDocumentView(testView1, string.Empty);
-                avalonDockViewHost.AddToolView(testView2, ToolViewLocation.Left, string.Empty);
+                avalonDockViewHost.AddToolView(testView2, ToolViewLocation.Left, string.Empty, string.Empty);
                 SetActiveView(avalonDockViewHost, testView1);
 
                 avalonDockViewHost.ActiveDocumentViewChanging += (sender, args) => activeDocumentViewChangingCounter++;
@@ -316,7 +316,7 @@
                 avalonDockViewHost.AddDocumentView(testView2, string.Empty);
                 avalonDockViewHost.AddDocumentView(testView3, string.Empty);
                 avalonDockViewHost.AddDocumentView(testView4, string.Empty);
-                avalonDockViewHost.AddToolView(testView5, ToolViewLocation.Left, string.Empty);
+                avalonDockViewHost.AddToolView(testView5, ToolViewLocation.Left, string.Empty, string.Empty);
 
                 SetActiveView(avalonDockViewHost, testView1);
 
@@ -357,7 +357,7 @@
                 avalonDockViewHost.AddDocumentView(testView2, string.Empty);
                 avalonDockViewHost.AddDocumentView(testView3, string.Empty);
                 avalonDockViewHost.AddDocumentView(testView4, string.Empty);
-                avalonDockViewHost.AddToolView(testView5, ToolViewLocation.Left, string.Empty);
+                avalonDockViewHost.AddToolView(testView5, ToolViewLocation.Left, string.Empty, string.Empty);
 
                 SetActiveView(avalonDockViewHost, testView3);
 
@@ -490,7 +490,7 @@
                 avalonDockViewHost.ViewOpened += (sender, args) => viewOpenedCounter++;
 
                 // Call
-                avalonDockViewHost.AddToolView(testView, ToolViewLocation.Left, symbol);
+                avalonDockViewHost.AddToolView(testView, ToolViewLocation.Left, string.Empty, symbol);
 
                 // Assert
                 CollectionAssert.IsEmpty(avalonDockViewHost.ToolViews);
@@ -529,7 +529,7 @@
                 };
 
                 // Call
-                avalonDockViewHost.AddToolView(testView, toolViewLocation, symbol);
+                avalonDockViewHost.AddToolView(testView, toolViewLocation, string.Empty, symbol);
 
                 // Assert
                 CollectionAssert.AreEqual(
@@ -554,7 +554,7 @@
             using (var testView = new TestView())
             {
                 // Call
-                void Call() => avalonDockViewHost.AddToolView(testView, (ToolViewLocation) invalidLocation, string.Empty);
+                void Call() => avalonDockViewHost.AddToolView(testView, (ToolViewLocation) invalidLocation, string.Empty, string.Empty);
 
                 // Assert
                 string expectedMessage = $"The value of argument 'toolViewLocation' ({invalidLocation}) is invalid for Enum type 'ToolViewLocation'.";
@@ -578,7 +578,7 @@
                 SetActiveView(avalonDockViewHost, testDocumentView);
 
                 // Call
-                avalonDockViewHost.AddToolView(testToolView, ToolViewLocation.Left, string.Empty);
+                avalonDockViewHost.AddToolView(testToolView, ToolViewLocation.Left, string.Empty, string.Empty);
 
                 // Assert
                 Assert.AreSame(testDocumentView, avalonDockViewHost.ActiveDocumentView);
@@ -595,14 +595,14 @@
 
             using (var avalonDockViewHost = new AvalonDockViewHost())
             {
-                avalonDockViewHost.AddToolView(testView1, ToolViewLocation.Left, string.Empty);
-                avalonDockViewHost.AddToolView(testView2, ToolViewLocation.Left, string.Empty);
+                avalonDockViewHost.AddToolView(testView1, ToolViewLocation.Left, string.Empty, string.Empty);
+                avalonDockViewHost.AddToolView(testView2, ToolViewLocation.Left, string.Empty, string.Empty);
 
                 var viewOpenedCounter = 0;
                 avalonDockViewHost.ViewOpened += (sender, args) => viewOpenedCounter++;
 
                 // Call
-                avalonDockViewHost.AddToolView(testView1, ToolViewLocation.Right, string.Empty);
+                avalonDockViewHost.AddToolView(testView1, ToolViewLocation.Right, string.Empty, string.Empty);
 
                 // Assert
                 CollectionAssert.AreEqual(
@@ -625,8 +625,8 @@
 
             using (var avalonDockViewHost = new AvalonDockViewHost())
             {
-                avalonDockViewHost.AddToolView(testView1, ToolViewLocation.Left, string.Empty);
-                avalonDockViewHost.AddToolView(testView2, ToolViewLocation.Left, string.Empty);
+                avalonDockViewHost.AddToolView(testView1, ToolViewLocation.Left, string.Empty, string.Empty);
+                avalonDockViewHost.AddToolView(testView2, ToolViewLocation.Left, string.Empty, string.Empty);
 
                 // Precondition
                 CollectionAssert.AreEqual(
@@ -659,7 +659,7 @@
 
             using (var avalonDockViewHost = new AvalonDockViewHost())
             {
-                avalonDockViewHost.AddToolView(testView, ToolViewLocation.Left, string.Empty);
+                avalonDockViewHost.AddToolView(testView, ToolViewLocation.Left, string.Empty, string.Empty);
 
                 avalonDockViewHost.ViewClosed += (sender, args) =>
                 {
@@ -695,7 +695,7 @@
                 avalonDockViewHost.AddDocumentView(testView2, string.Empty);
                 avalonDockViewHost.AddDocumentView(testView3, string.Empty);
                 avalonDockViewHost.AddDocumentView(testView4, string.Empty);
-                avalonDockViewHost.AddToolView(testView5, ToolViewLocation.Left, string.Empty);
+                avalonDockViewHost.AddToolView(testView5, ToolViewLocation.Left, string.Empty, string.Empty);
 
                 SetActiveView(avalonDockViewHost, testView3);
                 SetActiveView(avalonDockViewHost, testView5);
@@ -731,8 +731,8 @@
 
             using (var avalonDockViewHost = new AvalonDockViewHost())
             {
-                avalonDockViewHost.AddToolView(testView1, ToolViewLocation.Left, string.Empty);
-                avalonDockViewHost.AddToolView(testView2, ToolViewLocation.Bottom, string.Empty);
+                avalonDockViewHost.AddToolView(testView1, ToolViewLocation.Left, string.Empty, string.Empty);
+                avalonDockViewHost.AddToolView(testView2, ToolViewLocation.Bottom, string.Empty, string.Empty);
                 SetActiveView(avalonDockViewHost, testView1);
 
                 avalonDockViewHost.ViewBroughtToFront += (sender, args) => viewBroughtToFrontCounter++;
@@ -765,8 +765,8 @@
 
             using (var avalonDockViewHost = new AvalonDockViewHost())
             {
-                avalonDockViewHost.AddToolView(testView1, ToolViewLocation.Left, string.Empty);
-                avalonDockViewHost.AddToolView(testView2, ToolViewLocation.Bottom, string.Empty);
+                avalonDockViewHost.AddToolView(testView1, ToolViewLocation.Left, string.Empty, string.Empty);
+                avalonDockViewHost.AddToolView(testView2, ToolViewLocation.Bottom, string.Empty, string.Empty);
                 SetActiveView(avalonDockViewHost, testView2);
 
                 avalonDockViewHost.ViewBroughtToFront += (sender, args) => viewBroughtToFrontCounter++;
@@ -794,7 +794,7 @@
 
             using (var avalonDockViewHost = new AvalonDockViewHost())
             {
-                avalonDockViewHost.AddToolView(testView, ToolViewLocation.Left, string.Empty);
+                avalonDockViewHost.AddToolView(testView, ToolViewLocation.Left, string.Empty, string.Empty);
 
                 // Precondition
                 Assert.IsFalse(IsImageSet(avalonDockViewHost, testView));
Index: Core/Gui/test/Core.Gui.Test/GuiCoreTest.cs
===================================================================
diff -u -r0c2079726458d902cc7b2424907383bfc68ba111 -rbbb6068d01161dfc28efeb537d9c4ff324c373b8
--- Core/Gui/test/Core.Gui.Test/GuiCoreTest.cs	(.../GuiCoreTest.cs)	(revision 0c2079726458d902cc7b2424907383bfc68ba111)
+++ Core/Gui/test/Core.Gui.Test/GuiCoreTest.cs	(.../GuiCoreTest.cs)	(revision bbb6068d01161dfc28efeb537d9c4ff324c373b8)
@@ -393,7 +393,7 @@
                 var gui = new GuiCore(new MainWindow(), projectStore, projectMigrator, projectFactory, new GuiCoreSettings());
                 gui.Run();
 
-                gui.ViewHost.AddToolView(toolView, ToolViewLocation.Left, string.Empty);
+                gui.ViewHost.AddToolView(toolView, ToolViewLocation.Left, string.Empty, string.Empty);
 
                 // Call
                 gui.Dispose();