diff --git a/Disp/DemoUtil.cs b/Disp/DemoUtil.cs
index 4ec0391..921fc3c 100644
--- a/Disp/DemoUtil.cs
+++ b/Disp/DemoUtil.cs
@@ -26,7 +26,8 @@ public static class DemoUtil
 	/// <param name="displayee">The object that implements IDisplayee to be rendered</param>
 	public static void RunApplication(string title, IDisplayee displayee)
 	{
-		LocalApp.AppBegin();
+		using var loggerFactory = Microsoft.Extensions.Logging.LoggerFactory.Create(b => b.AddConsole());
+		LocalApp.AppBegin(loggerFactory.CreateLogger("Hi.Sample.Wpf"));
 		Application app = new Application();
 		app.Exit += (o, e) =>
 		{
diff --git a/Machining/DemoMillingByCutterLocation.cs b/Machining/DemoMillingByCutterLocation.cs
index 8c37fab..c65ba9b 100644
--- a/Machining/DemoMillingByCutterLocation.cs
+++ b/Machining/DemoMillingByCutterLocation.cs
@@ -1,4 +1,4 @@
-using Hi.Common;
+using Hi.Common.Messages;
 using Hi.Disp;
 using Hi.Geom;
 using Hi.Geom.Resolution;
@@ -34,7 +34,8 @@ namespace Sample.Machining
 			new Cylindroid(new PairZr(-h, 18), new PairZr(0, 18))
 				.GenStl(new PolarResolution2d(1, MathUtil.ToRad(15))).WriteBin(stlFile_CylinderR18);
 
-			LocalApp.AppBegin();
+			using var loggerFactory = Microsoft.Extensions.Logging.LoggerFactory.Create(b => b.AddConsole());
+			LocalApp.AppBegin(loggerFactory.CreateLogger("Hi.Sample.Wpf"));
 
 			LocalProjectService localProjectService = new LocalProjectService();
 
diff --git a/Machining/DemoRenderingMachiningProcessAndStripPosSelection.cs b/Machining/DemoRenderingMachiningProcessAndStripPosSelection.cs
index 087446c..e2215f2 100644
--- a/Machining/DemoRenderingMachiningProcessAndStripPosSelection.cs
+++ b/Machining/DemoRenderingMachiningProcessAndStripPosSelection.cs
@@ -22,7 +22,8 @@ namespace Sample.Machining
         [STAThread]
         static void Main(string[] args)
         {
-            LocalApp.AppBegin();
+            using var loggerFactory = Microsoft.Extensions.Logging.LoggerFactory.Create(b => b.AddConsole());
+            LocalApp.AppBegin(loggerFactory.CreateLogger("Hi.Sample.Wpf"));
 			LocalProjectService localProjectService = new LocalProjectService();
 
 			#region Load Machining Project