diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index 8cf3974..0f78cab 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -3,7 +3,7 @@
 {
 	"name": "Intro to .NET webdev",
 	// Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
-	"image": "mcr.microsoft.com/devcontainers/dotnet:8.0",
+	"image": "mcr.microsoft.com/devcontainers/dotnet:9.0",
 
 	// Features to add to the dev container. More info: https://containers.dev/features.
   	"features": {},
diff --git a/.github/workflows/dotnet.yml b/.github/workflows/dotnet.yml
index 7d5d7bd..93939c7 100644
--- a/.github/workflows/dotnet.yml
+++ b/.github/workflows/dotnet.yml
@@ -10,7 +10,7 @@ on:
     branches: [ main ]
 
 env:
-  DOTNET_VERSION: '8.0.x' # The .NET SDK version to use
+  DOTNET_VERSION: '9.0.x' # The .NET SDK version to use
 
 jobs:
   build:
diff --git a/2-csharp/lesson-2-projects/challenge-project/Final/Final.csproj b/2-csharp/lesson-2-projects/challenge-project/Final/Final.csproj
index 91b464a..694035b 100644
--- a/2-csharp/lesson-2-projects/challenge-project/Final/Final.csproj
+++ b/2-csharp/lesson-2-projects/challenge-project/Final/Final.csproj
@@ -2,7 +2,7 @@
 
   
     Exe
-    net8.0
+    net9.0
     enable
     enable
   
diff --git a/2-csharp/lesson-2-projects/guided-project/Starter/Starter.csproj b/2-csharp/lesson-2-projects/guided-project/Starter/Starter.csproj
index 91b464a..694035b 100644
--- a/2-csharp/lesson-2-projects/guided-project/Starter/Starter.csproj
+++ b/2-csharp/lesson-2-projects/guided-project/Starter/Starter.csproj
@@ -2,7 +2,7 @@
 
   
     Exe
-    net8.0
+    net9.0
     enable
     enable
   
diff --git a/2-csharp/lesson-3-projects/challenge-project/Final/Final.csproj b/2-csharp/lesson-3-projects/challenge-project/Final/Final.csproj
index 91b464a..694035b 100644
--- a/2-csharp/lesson-3-projects/challenge-project/Final/Final.csproj
+++ b/2-csharp/lesson-3-projects/challenge-project/Final/Final.csproj
@@ -2,7 +2,7 @@
 
   
     Exe
-    net8.0
+    net9.0
     enable
     enable
   
diff --git a/2-csharp/lesson-3-projects/challenge-project/Starter/Starter.csproj b/2-csharp/lesson-3-projects/challenge-project/Starter/Starter.csproj
index 91b464a..694035b 100644
--- a/2-csharp/lesson-3-projects/challenge-project/Starter/Starter.csproj
+++ b/2-csharp/lesson-3-projects/challenge-project/Starter/Starter.csproj
@@ -2,7 +2,7 @@
 
   
     Exe
-    net8.0
+    net9.0
     enable
     enable
   
diff --git a/2-csharp/lesson-3-projects/guided-project/Final/Final.csproj b/2-csharp/lesson-3-projects/guided-project/Final/Final.csproj
index 91b464a..694035b 100644
--- a/2-csharp/lesson-3-projects/guided-project/Final/Final.csproj
+++ b/2-csharp/lesson-3-projects/guided-project/Final/Final.csproj
@@ -2,7 +2,7 @@
 
   
     Exe
-    net8.0
+    net9.0
     enable
     enable
   
diff --git a/2-csharp/lesson-3-projects/guided-project/Starter/Starter.csproj b/2-csharp/lesson-3-projects/guided-project/Starter/Starter.csproj
index 91b464a..694035b 100644
--- a/2-csharp/lesson-3-projects/guided-project/Starter/Starter.csproj
+++ b/2-csharp/lesson-3-projects/guided-project/Starter/Starter.csproj
@@ -2,7 +2,7 @@
 
   
     Exe
-    net8.0
+    net9.0
     enable
     enable
   
diff --git a/2-csharp/lesson-4-projects/challenge-project/Final/Final.csproj b/2-csharp/lesson-4-projects/challenge-project/Final/Final.csproj
index 91b464a..694035b 100644
--- a/2-csharp/lesson-4-projects/challenge-project/Final/Final.csproj
+++ b/2-csharp/lesson-4-projects/challenge-project/Final/Final.csproj
@@ -2,7 +2,7 @@
 
   
     Exe
-    net8.0
+    net9.0
     enable
     enable
   
diff --git a/2-csharp/lesson-4-projects/challenge-project/Starter/Starter.csproj b/2-csharp/lesson-4-projects/challenge-project/Starter/Starter.csproj
index 91b464a..694035b 100644
--- a/2-csharp/lesson-4-projects/challenge-project/Starter/Starter.csproj
+++ b/2-csharp/lesson-4-projects/challenge-project/Starter/Starter.csproj
@@ -2,7 +2,7 @@
 
   
     Exe
-    net8.0
+    net9.0
     enable
     enable
   
diff --git a/2-csharp/lesson-4-projects/guided-project/Final/Final.csproj b/2-csharp/lesson-4-projects/guided-project/Final/Final.csproj
index 91b464a..694035b 100644
--- a/2-csharp/lesson-4-projects/guided-project/Final/Final.csproj
+++ b/2-csharp/lesson-4-projects/guided-project/Final/Final.csproj
@@ -2,7 +2,7 @@
 
   
     Exe
-    net8.0
+    net9.0
     enable
     enable
   
diff --git a/2-csharp/lesson-4-projects/guided-project/Starter/Starter.csproj b/2-csharp/lesson-4-projects/guided-project/Starter/Starter.csproj
index 91b464a..694035b 100644
--- a/2-csharp/lesson-4-projects/guided-project/Starter/Starter.csproj
+++ b/2-csharp/lesson-4-projects/guided-project/Starter/Starter.csproj
@@ -2,7 +2,7 @@
 
   
     Exe
-    net8.0
+    net9.0
     enable
     enable
   
diff --git a/2-csharp/lesson-5-projects/challenge-project/Final/Final.csproj b/2-csharp/lesson-5-projects/challenge-project/Final/Final.csproj
index 91b464a..694035b 100644
--- a/2-csharp/lesson-5-projects/challenge-project/Final/Final.csproj
+++ b/2-csharp/lesson-5-projects/challenge-project/Final/Final.csproj
@@ -2,7 +2,7 @@
 
   
     Exe
-    net8.0
+    net9.0
     enable
     enable
   
diff --git a/2-csharp/lesson-5-projects/challenge-project/Starter/Starter.csproj b/2-csharp/lesson-5-projects/challenge-project/Starter/Starter.csproj
index 91b464a..694035b 100644
--- a/2-csharp/lesson-5-projects/challenge-project/Starter/Starter.csproj
+++ b/2-csharp/lesson-5-projects/challenge-project/Starter/Starter.csproj
@@ -2,7 +2,7 @@
 
   
     Exe
-    net8.0
+    net9.0
     enable
     enable
   
diff --git a/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza.sln b/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza.sln
index b32542f..876c4da 100644
--- a/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza.sln
+++ b/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza.sln
@@ -1,9 +1,9 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio Version 17
-VisualStudioVersion = 17.7.33808.371
+VisualStudioVersion = 17.14.36105.17 d17.14
 MinimumVisualStudioVersion = 10.0.40219.1
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "RazorPagesPizza", "RazorPagesPizza\RazorPagesPizza.csproj", "{ADA085D1-1380-4955-A58D-FD688EC5B4B9}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "RazorPagesPizza", "RazorPagesPizza\RazorPagesPizza.csproj", "{243A1A33-7C10-48AA-B690-7D574211C5A8}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -11,15 +11,15 @@ Global
 		Release|Any CPU = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{ADA085D1-1380-4955-A58D-FD688EC5B4B9}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{ADA085D1-1380-4955-A58D-FD688EC5B4B9}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{ADA085D1-1380-4955-A58D-FD688EC5B4B9}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{ADA085D1-1380-4955-A58D-FD688EC5B4B9}.Release|Any CPU.Build.0 = Release|Any CPU
+		{243A1A33-7C10-48AA-B690-7D574211C5A8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{243A1A33-7C10-48AA-B690-7D574211C5A8}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{243A1A33-7C10-48AA-B690-7D574211C5A8}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{243A1A33-7C10-48AA-B690-7D574211C5A8}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
-		SolutionGuid = {7052E9F1-F97B-4A22-AEA8-66D01D921E93}
+		SolutionGuid = {768BD1A9-D918-42C0-A4FA-FC6B038F477E}
 	EndGlobalSection
 EndGlobal
diff --git a/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Error.cshtml.cs b/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Error.cshtml.cs
index 36cfb3f..78cb44b 100644
--- a/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Error.cshtml.cs
+++ b/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Error.cshtml.cs
@@ -1,6 +1,6 @@
+using System.Diagnostics;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.RazorPages;
-using System.Diagnostics;
 
 namespace RazorPagesPizza.Pages
 {
@@ -24,4 +24,5 @@ public void OnGet()
             RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier;
         }
     }
-}
\ No newline at end of file
+
+}
diff --git a/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Index.cshtml b/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Index.cshtml
index b5f0c15..f9ff8d4 100644
--- a/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Index.cshtml
+++ b/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Index.cshtml
@@ -6,5 +6,5 @@
 
 
diff --git a/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Index.cshtml.cs b/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Index.cshtml.cs
index c307c7e..f4c5b06 100644
--- a/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Index.cshtml.cs
+++ b/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Index.cshtml.cs
@@ -1,4 +1,4 @@
-using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.RazorPages;
 
 namespace RazorPagesPizza.Pages
@@ -17,4 +17,4 @@ public void OnGet()
 
         }
     }
-}
\ No newline at end of file
+}
diff --git a/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Privacy.cshtml.cs b/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Privacy.cshtml.cs
index 30dd3f0..955daf1 100644
--- a/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Privacy.cshtml.cs
+++ b/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Privacy.cshtml.cs
@@ -16,4 +16,5 @@ public void OnGet()
         {
         }
     }
-}
\ No newline at end of file
+
+}
diff --git a/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Shared/_Layout.cshtml b/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Shared/_Layout.cshtml
index 4673737..5c2776e 100644
--- a/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Shared/_Layout.cshtml
+++ b/3-razor-pages/0-start/RazorPagesPizza/RazorPagesPizza/Pages/Shared/_Layout.cshtml
@@ -4,6 +4,7 @@
     
     
     @ViewData["Title"] - RazorPagesPizza
+    
     
     
     
@@ -38,7 +39,7 @@
 
     
 
@@ -48,4 +49,4 @@
 
     @await RenderSectionAsync("Scripts", required: false)