diff --git a/AppStub/AppStub.csproj b/AppStub/AppStub.csproj
index 97c092f..2b481ce 100644
--- a/AppStub/AppStub.csproj
+++ b/AppStub/AppStub.csproj
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props')" />
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -10,6 +11,8 @@
     <AssemblyName>AppStub</AssemblyName>
     <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
+    <NuGetPackageImportStamp>
+    </NuGetPackageImportStamp>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <PlatformTarget>AnyCPU</PlatformTarget>
@@ -20,6 +23,7 @@
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <PlatformTarget>AnyCPU</PlatformTarget>
@@ -29,6 +33,7 @@
     <DefineConstants>TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
   <PropertyGroup>
     <StartupObject />
@@ -48,6 +53,13 @@
   </ItemGroup>
   <ItemGroup>
     <None Include="App.config" />
+    <None Include="packages.config" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>Dieses Projekt verweist auf mindestens ein NuGet-Paket, das auf diesem Computer fehlt. Verwenden Sie die Wiederherstellung von NuGet-Paketen, um die fehlenden Dateien herunterzuladen. Weitere Informationen finden Sie unter "http://go.microsoft.com/fwlink/?LinkID=322105". Die fehlende Datei ist "{0}".</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props'))" />
+  </Target>
 </Project>
\ No newline at end of file
diff --git a/AppStub/packages.config b/AppStub/packages.config
new file mode 100644
index 0000000..0a67ff9
--- /dev/null
+++ b/AppStub/packages.config
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  <package id="Microsoft.Net.Compilers" version="2.9.0" targetFramework="net45" developmentDependency="true" />
+</packages>
\ No newline at end of file
diff --git a/Creator/App.config b/Creator/App.config
index b34a1ea..3697b26 100644
--- a/Creator/App.config
+++ b/Creator/App.config
@@ -1,29 +1,29 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <configuration>
     <startup> 
-        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.2"/>
+        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.2" />
     </startup>
   <runtime>
     <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
       <dependentAssembly>
-        <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral"/>
-        <bindingRedirect oldVersion="0.0.0.0-11.0.0.0" newVersion="11.0.0.0"/>
+        <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
+        <bindingRedirect oldVersion="0.0.0.0-11.0.0.0" newVersion="11.0.0.0" />
       </dependentAssembly>
       <dependentAssembly>
-        <assemblyIdentity name="NuGet.Frameworks" publicKeyToken="31bf3856ad364e35" culture="neutral"/>
-        <bindingRedirect oldVersion="0.0.0.0-4.5.0.4" newVersion="4.5.0.4"/>
+        <assemblyIdentity name="NuGet.Frameworks" publicKeyToken="31bf3856ad364e35" culture="neutral" />
+        <bindingRedirect oldVersion="0.0.0.0-4.5.0.4" newVersion="4.5.0.4" />
       </dependentAssembly>
       <dependentAssembly>
-        <assemblyIdentity name="NuGet.Versioning" publicKeyToken="31bf3856ad364e35" culture="neutral"/>
-        <bindingRedirect oldVersion="0.0.0.0-4.5.0.4" newVersion="4.5.0.4"/>
+        <assemblyIdentity name="NuGet.Versioning" publicKeyToken="31bf3856ad364e35" culture="neutral" />
+        <bindingRedirect oldVersion="0.0.0.0-4.5.0.4" newVersion="4.5.0.4" />
       </dependentAssembly>
       <dependentAssembly>
-        <assemblyIdentity name="NuGet.Packaging" publicKeyToken="31bf3856ad364e35" culture="neutral"/>
-        <bindingRedirect oldVersion="0.0.0.0-4.5.0.4" newVersion="4.5.0.4"/>
+        <assemblyIdentity name="NuGet.Packaging" publicKeyToken="31bf3856ad364e35" culture="neutral" />
+        <bindingRedirect oldVersion="0.0.0.0-4.5.0.4" newVersion="4.5.0.4" />
       </dependentAssembly>
       <dependentAssembly>
-        <assemblyIdentity name="System.ValueTuple" publicKeyToken="cc7b13ffcd2ddd51" culture="neutral"/>
-        <bindingRedirect oldVersion="0.0.0.0-4.0.3.0" newVersion="4.0.3.0"/>
+        <assemblyIdentity name="System.ValueTuple" publicKeyToken="cc7b13ffcd2ddd51" culture="neutral" />
+        <bindingRedirect oldVersion="0.0.0.0-4.0.3.0" newVersion="4.0.3.0" />
       </dependentAssembly>
     </assemblyBinding>
   </runtime>
diff --git a/Creator/AssemblyFileInfo.cs b/Creator/AssemblyFileInfo.cs
index b975f59..9c0ac17 100644
--- a/Creator/AssemblyFileInfo.cs
+++ b/Creator/AssemblyFileInfo.cs
@@ -22,7 +22,7 @@ namespace KattekerCreator
             {
                 resourceInfo.Load(programFile);
                 if (resourceInfo.ResourceTypes.All(x => x.ResourceType != Kernel32.ResourceTypes.RT_VERSION)) return;
-                var versionResource = (VersionResource) resourceInfo[Kernel32.ResourceTypes.RT_VERSION].First();
+                var versionResource = (VersionResource) resourceInfo[Kernel32.ResourceTypes.RT_VERSION][0];
                 var stringFileInfo = ((StringFileInfo) versionResource[nameof(StringFileInfo)]).Strings
                     .FirstOrDefault().Value;
                 AssemblyIconPath = GetAssemblyIcon(programFile, tempDir);
diff --git a/Creator/KattekerCreator.csproj b/Creator/KattekerCreator.csproj
index 978905b..83720e6 100644
--- a/Creator/KattekerCreator.csproj
+++ b/Creator/KattekerCreator.csproj
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props')" />
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -27,6 +28,7 @@
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
     <Prefer32Bit>false</Prefer32Bit>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <PlatformTarget>AnyCPU</PlatformTarget>
@@ -37,6 +39,7 @@
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
     <Prefer32Bit>false</Prefer32Bit>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
   <PropertyGroup>
     <AutoGenerateBindingRedirects>false</AutoGenerateBindingRedirects>
@@ -105,6 +108,12 @@
     </ProjectReference>
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>Dieses Projekt verweist auf mindestens ein NuGet-Paket, das auf diesem Computer fehlt. Verwenden Sie die Wiederherstellung von NuGet-Paketen, um die fehlenden Dateien herunterzuladen. Weitere Informationen finden Sie unter "http://go.microsoft.com/fwlink/?LinkID=322105". Die fehlende Datei ist "{0}".</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props'))" />
+  </Target>
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.
   <Target Name="BeforeBuild">
diff --git a/Creator/Program.Arguments.cs b/Creator/Program.Arguments.cs
index 8a40ce7..7711ec8 100644
--- a/Creator/Program.Arguments.cs
+++ b/Creator/Program.Arguments.cs
@@ -50,6 +50,5 @@ namespace KattekerCreator
         private string FilterAsString { get; set; }
 
         private IEnumerable<string> Filter => string.IsNullOrWhiteSpace(FilterAsString) ? Enumerable.Empty<string>() : FilterAsString.Split(';');
-
     }
 }
\ No newline at end of file
diff --git a/Creator/packages.config b/Creator/packages.config
index 47b12ae..d2aa6b7 100644
--- a/Creator/packages.config
+++ b/Creator/packages.config
@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="McMaster.Extensions.CommandLineUtils" version="2.2.5" targetFramework="net462" />
+  <package id="Microsoft.Net.Compilers" version="2.9.0" targetFramework="net462" developmentDependency="true" />
   <package id="System.ValueTuple" version="4.5.0" targetFramework="net462" />
   <package id="Vestris.ResourceLib" version="1.6.422" targetFramework="net462" />
 </packages>
\ No newline at end of file
diff --git a/Example/Example.csproj b/Example/Example.csproj
index cb3676b..bf06c9e 100644
--- a/Example/Example.csproj
+++ b/Example/Example.csproj
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props')" />
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -13,6 +14,8 @@
     <ProjectTypeGuids>{60dc8134-eba5-43b8-bcc9-bb4bc16c2548};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
     <WarningLevel>4</WarningLevel>
     <TargetFrameworkProfile />
+    <NuGetPackageImportStamp>
+    </NuGetPackageImportStamp>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <PlatformTarget>AnyCPU</PlatformTarget>
@@ -24,6 +27,7 @@
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
     <Prefer32Bit>false</Prefer32Bit>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <PlatformTarget>x64</PlatformTarget>
@@ -33,6 +37,7 @@
     <DefineConstants>TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
   <PropertyGroup>
     <ApplicationIcon>nsis3-install.ico</ApplicationIcon>
@@ -141,4 +146,10 @@
     <Resource Include="nsis3-install.ico" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>Dieses Projekt verweist auf mindestens ein NuGet-Paket, das auf diesem Computer fehlt. Verwenden Sie die Wiederherstellung von NuGet-Paketen, um die fehlenden Dateien herunterzuladen. Weitere Informationen finden Sie unter "http://go.microsoft.com/fwlink/?LinkID=322105". Die fehlende Datei ist "{0}".</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props'))" />
+  </Target>
 </Project>
\ No newline at end of file
diff --git a/Example/packages.config b/Example/packages.config
index 25ca2a4..c59d86b 100644
--- a/Example/packages.config
+++ b/Example/packages.config
@@ -4,6 +4,7 @@
   <package id="CommonServiceLocator" version="1.3" targetFramework="net45" />
   <package id="MaterialDesignColors" version="1.1.2" targetFramework="net45" />
   <package id="MaterialDesignThemes" version="2.4.1.1101" targetFramework="net45" />
+  <package id="Microsoft.Net.Compilers" version="2.9.0" targetFramework="net45" developmentDependency="true" />
   <package id="Prism.Autofac" version="6.3.0" targetFramework="net45" />
   <package id="Prism.Core" version="6.3.0" targetFramework="net45" />
   <package id="Prism.Wpf" version="6.3.0" targetFramework="net45" />
diff --git a/Katteker.Gui/Katteker.UserInterface.csproj b/Katteker.Gui/Katteker.UserInterface.csproj
index ddc127d..5fbf5e7 100644
--- a/Katteker.Gui/Katteker.UserInterface.csproj
+++ b/Katteker.Gui/Katteker.UserInterface.csproj
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props')" />
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -13,6 +14,8 @@
     <FileAlignment>512</FileAlignment>
     <SolutionDir Condition="$(SolutionDir) == '' Or $(SolutionDir) == '*Undefined*'">..\</SolutionDir>
     <RestorePackages>true</RestorePackages>
+    <NuGetPackageImportStamp>
+    </NuGetPackageImportStamp>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -23,6 +26,7 @@
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
     <DocumentationFile>bin\Debug\Katteker.UserInterface.xml</DocumentationFile>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
@@ -32,6 +36,7 @@
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
     <DocumentationFile>bin\Release\Katteker.UserInterface.xml</DocumentationFile>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="Microsoft.CSharp" />
@@ -82,6 +87,12 @@
     <PostBuildEvent>
     </PostBuildEvent>
   </PropertyGroup>
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>Dieses Projekt verweist auf mindestens ein NuGet-Paket, das auf diesem Computer fehlt. Verwenden Sie die Wiederherstellung von NuGet-Paketen, um die fehlenden Dateien herunterzuladen. Weitere Informationen finden Sie unter "http://go.microsoft.com/fwlink/?LinkID=322105". Die fehlende Datei ist "{0}".</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props'))" />
+  </Target>
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.
   <Target Name="BeforeBuild">
diff --git a/Katteker.Gui/packages.config b/Katteker.Gui/packages.config
index 82a1859..0a67ff9 100644
--- a/Katteker.Gui/packages.config
+++ b/Katteker.Gui/packages.config
@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="Katteker" version="1.1.0" targetFramework="net45" />
+  <package id="Microsoft.Net.Compilers" version="2.9.0" targetFramework="net45" developmentDependency="true" />
 </packages>
\ No newline at end of file
diff --git a/Katteker.Test/Katteker.Test.csproj b/Katteker.Test/Katteker.Test.csproj
index f105306..399d921 100644
--- a/Katteker.Test/Katteker.Test.csproj
+++ b/Katteker.Test/Katteker.Test.csproj
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="15.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props')" />
   <Import Project="..\packages\NUnit3TestAdapter.3.10.0\build\net35\NUnit3TestAdapter.props" Condition="Exists('..\packages\NUnit3TestAdapter.3.10.0\build\net35\NUnit3TestAdapter.props')" />
   <Import Project="..\packages\NUnit.3.10.1\build\NUnit.props" Condition="Exists('..\packages\NUnit.3.10.1\build\NUnit.props')" />
   <PropertyGroup>
@@ -30,6 +31,7 @@
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
@@ -38,6 +40,7 @@
     <DefineConstants>TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="nunit.framework, Version=3.10.1.0, Culture=neutral, PublicKeyToken=2638cd05610744eb, processorArchitecture=MSIL">
@@ -137,5 +140,6 @@
     </PropertyGroup>
     <Error Condition="!Exists('..\packages\NUnit.3.10.1\build\NUnit.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\NUnit.3.10.1\build\NUnit.props'))" />
     <Error Condition="!Exists('..\packages\NUnit3TestAdapter.3.10.0\build\net35\NUnit3TestAdapter.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\NUnit3TestAdapter.3.10.0\build\net35\NUnit3TestAdapter.props'))" />
+    <Error Condition="!Exists('..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props'))" />
   </Target>
 </Project>
\ No newline at end of file
diff --git a/Katteker.Test/packages.config b/Katteker.Test/packages.config
index 2c60fcf..8dff030 100644
--- a/Katteker.Test/packages.config
+++ b/Katteker.Test/packages.config
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
+  <package id="Microsoft.Net.Compilers" version="2.9.0" targetFramework="net462" developmentDependency="true" />
   <package id="NUnit" version="3.10.1" targetFramework="net461" />
   <package id="NUnit3TestAdapter" version="3.10.0" targetFramework="net461" />
 </packages>
\ No newline at end of file
diff --git a/Katteker/Katteker.csproj b/Katteker/Katteker.csproj
index a199d6f..2d685ec 100644
--- a/Katteker/Katteker.csproj
+++ b/Katteker/Katteker.csproj
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props')" />
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -12,6 +13,8 @@
     <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <TargetFrameworkProfile />
+    <NuGetPackageImportStamp>
+    </NuGetPackageImportStamp>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -22,6 +25,7 @@
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
     <DocumentationFile>bin\Debug\Katteker.xml</DocumentationFile>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
@@ -30,6 +34,7 @@
     <DefineConstants>TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="System" />
@@ -51,5 +56,14 @@
     <Compile Include="Utility.cs" />
     <Compile Include="VersionUtils.cs" />
   </ItemGroup>
+  <ItemGroup>
+    <None Include="packages.config" />
+  </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>Dieses Projekt verweist auf mindestens ein NuGet-Paket, das auf diesem Computer fehlt. Verwenden Sie die Wiederherstellung von NuGet-Paketen, um die fehlenden Dateien herunterzuladen. Weitere Informationen finden Sie unter "http://go.microsoft.com/fwlink/?LinkID=322105". Die fehlende Datei ist "{0}".</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Microsoft.Net.Compilers.2.9.0\build\Microsoft.Net.Compilers.props'))" />
+  </Target>
 </Project>
\ No newline at end of file
diff --git a/Katteker/packages.config b/Katteker/packages.config
new file mode 100644
index 0000000..0a67ff9
--- /dev/null
+++ b/Katteker/packages.config
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  <package id="Microsoft.Net.Compilers" version="2.9.0" targetFramework="net45" developmentDependency="true" />
+</packages>
\ No newline at end of file