not working on windows 8.1 with .Net 8

Queries/App.config

-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <configuration>
   <configSections>
     <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
-    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
+    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false"/>
   </configSections>
   <startup>
-    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.8" />
+    <!--  v4.8 doesn't not support my OS Windows 8.1-->
+    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1"/>
   </startup>
   <connectionStrings>
-    <add name="PlutoContext" connectionString="data source=.\SQLEXPRESS;initial catalog=Pluto_Queries;integrated security=True;MultipleActiveResultSets=True;App=EntityFramework" providerName="System.Data.SqlClient" />
+    <add name="PlutoContext" connectionString="data source=.\SQLEXPRESS;initial catalog=Pluto_Queries;integrated security=True;MultipleActiveResultSets=True;App=EntityFramework" providerName="System.Data.SqlClient"/>
   </connectionStrings>
   <entityFramework>
     <providers>
-      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
+      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer"/>
     </providers>
   </entityFramework>
-</configuration>
\ No newline at end of file
+</configuration>

Queries/Program.cs

@@ -15,7 +15,7 @@ namespace Queries
                 // Example2
                 var courses = unitOfWork.Courses.GetCoursesWithAuthors(1, 4);
 
-                Console.WriteLine(course.Name);
+                Console.WriteLine(course.Name);     //System.NullReferenceException must be handeld! 
 
                 // Example3
                 /*var author = unitOfWork.Authors.GetAuthorWithCourses(1);

Queries/Queries.csproj

@@ -10,7 +10,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>Queries</RootNamespace>
     <AssemblyName>Queries</AssemblyName>
-    <TargetFrameworkVersion>v4.8</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <TargetFrameworkProfile />
     <NuGetPackageImportStamp>