diff --git a/.github/workflows/codebreaker-lib-analyzers-stable.yml b/.github/workflows/codebreaker-lib-analyzers-stable.yml
index 79427020..e5024aa5 100644
--- a/.github/workflows/codebreaker-lib-analyzers-stable.yml
+++ b/.github/workflows/codebreaker-lib-analyzers-stable.yml
@@ -22,7 +22,7 @@ jobs:
       - name: Setup .NET
         uses: actions/setup-dotnet@v4
         with: 
-          dotnet-version: 8.0.x
+          dotnet-version: 9.0.x
 
       - name: Build the library
         run: dotnet build -c Release ${{ env.solutionfile-path }}
diff --git a/.github/workflows/codebreaker-lib-analyzers.yml b/.github/workflows/codebreaker-lib-analyzers.yml
index 234867f6..c90aca9b 100644
--- a/.github/workflows/codebreaker-lib-analyzers.yml
+++ b/.github/workflows/codebreaker-lib-analyzers.yml
@@ -27,7 +27,7 @@ jobs:
       version-offset: 38
       solutionfile-path: src/Codebreaker.Analyzers.sln
       projectfile-path: src/services/common/Codebreaker.GameAPIs.Analyzers/Codebreaker.Analyzers.csproj
-      dotnet-version: '8.0.x'
+      dotnet-version: '9.0.x'
       artifact-name: codebreaker-analyzers
       branch-name: main
 
@@ -38,6 +38,8 @@ jobs:
       artifact-name: codebreaker-analyzers
     secrets: inherit
 
+  # NuGet publish is now done with codebreaker-lib-stable.yml
+  # In case a preview version will be published again to NuGet, this can be uncommented.
   # publishnuget:
   #   uses: CodebreakerApp/Codebreaker.Backend/.github/workflows/publishnuget-nugetserver.yml@main
   #   needs: publishdevops
diff --git a/src/services/common/Codebreaker.GameAPIs.Analyzers.Tests/Codebreaker.GameAPIs.Analyzers.Tests.csproj b/src/services/common/Codebreaker.GameAPIs.Analyzers.Tests/Codebreaker.GameAPIs.Analyzers.Tests.csproj
index b78889d8..ef967361 100644
--- a/src/services/common/Codebreaker.GameAPIs.Analyzers.Tests/Codebreaker.GameAPIs.Analyzers.Tests.csproj
+++ b/src/services/common/Codebreaker.GameAPIs.Analyzers.Tests/Codebreaker.GameAPIs.Analyzers.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net9.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
 
@@ -10,15 +10,15 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
-    <PackageReference Include="Microsoft.VisualStudio.Azure.Containers.Tools.Targets" Version="1.19.5" />
-    <PackageReference Include="Moq" Version="4.20.70" />
-    <PackageReference Include="xunit" Version="2.6.3" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.5">
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
+    <PackageReference Include="Microsoft.VisualStudio.Azure.Containers.Tools.Targets" Version="1.21.0" />
+    <PackageReference Include="Moq" Version="4.20.72" />
+    <PackageReference Include="xunit" Version="2.9.2" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
-    <PackageReference Include="coverlet.collector" Version="6.0.0">
+    <PackageReference Include="coverlet.collector" Version="6.0.2">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
diff --git a/src/services/common/Codebreaker.GameAPIs.Analyzers/Analyzers/GameGuessAnalyzer.cs b/src/services/common/Codebreaker.GameAPIs.Analyzers/Analyzers/GameGuessAnalyzer.cs
index 2fab97bd..b51bbb51 100644
--- a/src/services/common/Codebreaker.GameAPIs.Analyzers/Analyzers/GameGuessAnalyzer.cs
+++ b/src/services/common/Codebreaker.GameAPIs.Analyzers/Analyzers/GameGuessAnalyzer.cs
@@ -8,7 +8,7 @@
 public abstract class GameGuessAnalyzer<TField, TResult>(IGame game, TField[] guesses, int moveNumber) : IGameGuessAnalyzer<TResult>
     where TResult : struct
 {
-    protected readonly IGame _game = game;
+    private protected readonly IGame _game = game;
     private readonly int _moveNumber = moveNumber;
 
     protected TField[] Guesses { get; private set; } = guesses;
@@ -32,7 +32,9 @@ private void ValidateGuess()
     {
         /// The number of codes in the game does not match the number of pegs in the move.
         if (_game.NumberCodes != Guesses.Length)
+        {
             throw new ArgumentException($"Invalid guess number {Guesses.Length} for {_game.NumberCodes} code numbers") { HResult = 4200 };
+        }
 
         ValidateGuessValues();
 
diff --git a/src/services/common/Codebreaker.GameAPIs.Analyzers/Codebreaker.Analyzers.csproj b/src/services/common/Codebreaker.GameAPIs.Analyzers/Codebreaker.Analyzers.csproj
index 0a4806ab..a2609a6e 100644
--- a/src/services/common/Codebreaker.GameAPIs.Analyzers/Codebreaker.Analyzers.csproj
+++ b/src/services/common/Codebreaker.GameAPIs.Analyzers/Codebreaker.Analyzers.csproj
@@ -2,10 +2,10 @@
 
   <PropertyGroup>
     <PackageId>CNinnovation.Codebreaker.Analyzers</PackageId>
-    <TargetFrameworks>net7.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
-    <LangVersion>latest</LangVersion>
+    <LangVersion>13.0</LangVersion>
     <PackageTags>
       Codebreaker;CNinnovation;GameAnalyzers
     </PackageTags>
@@ -15,10 +15,7 @@
     </Description>
     <PackageReadmeFile>readme.md</PackageReadmeFile>
     <PackageIcon>codebreaker.jpeg</PackageIcon>
-  </PropertyGroup>
-
-  <PropertyGroup>
-    <IsAotCompatible Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net8.0'))">true</IsAotCompatible>
+    <IsAotCompatible>true</IsAotCompatible>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/services/common/Codebreaker.GameAPIs.Analyzers/Fields/ShapeAndColorField.cs b/src/services/common/Codebreaker.GameAPIs.Analyzers/Fields/ShapeAndColorField.cs
index d1901c51..1a2bd098 100644
--- a/src/services/common/Codebreaker.GameAPIs.Analyzers/Fields/ShapeAndColorField.cs
+++ b/src/services/common/Codebreaker.GameAPIs.Analyzers/Fields/ShapeAndColorField.cs
@@ -2,7 +2,7 @@
 
 public partial record class ShapeAndColorField(string Shape, string Color)
 {
-    internal static ShapeAndColorField Empty => new ShapeAndColorField(string.Empty, string.Empty);
+    internal static ShapeAndColorField Empty => new(string.Empty, string.Empty);
 
     private const char Separator = ';';
     public override string ToString() => $"{Shape}{Separator}{Color}";
diff --git a/src/services/common/Codebreaker.GameAPIs.Analyzers/Results/SimpleColorResult_ISpanParsable.cs b/src/services/common/Codebreaker.GameAPIs.Analyzers/Results/SimpleColorResult_ISpanParsable.cs
index 1f3a8686..6eb8de12 100644
--- a/src/services/common/Codebreaker.GameAPIs.Analyzers/Results/SimpleColorResult_ISpanParsable.cs
+++ b/src/services/common/Codebreaker.GameAPIs.Analyzers/Results/SimpleColorResult_ISpanParsable.cs
@@ -36,7 +36,7 @@ public static bool TryParse(ReadOnlySpan<char> s, IFormatProvider? provider, [Ma
             values[i] = (ResultValue)(s[j] - '0');
         }
         result = new SimpleColorResult(values);
-        return s != default;
+        return !s.IsEmpty;
     }
 
     public static bool TryParse([NotNullWhen(true)] string? s, IFormatProvider? provider, [MaybeNullWhen(false)] out SimpleColorResult result) =>