diff --git a/build.cake b/build.cake
index d882731aa..498be2407 100644
--- a/build.cake
+++ b/build.cake
@@ -114,11 +114,6 @@ public void BuildSolution()
         .WithProperty("TargetFramework", "netstandard2.0")
         .WithProperty("PublishDir", BIN_DIR + "netstandard2.0"));
 
-    DisplayBanner("Publishing ENGINE TESTS Project for NETCOREAPP2.1");
-    MSBuild(ENGINE_TESTS_PROJECT, CreateMSBuildSettings("Publish")
-        .WithProperty("TargetFramework", "netcoreapp2.1")
-        .WithProperty("PublishDir", BIN_DIR + "netcoreapp2.1"));
-
     // TODO: May not be needed
     foreach (var framework in new[] { "netcoreapp3.1", "net5.0" })
     {
@@ -129,6 +124,7 @@ public void BuildSolution()
     }
 }
 
+// TODO: Test this on linux to see if changes are needed
 private void BuildEachProjectSeparately()
 {
     DotNetRestore(SOLUTION_FILE);
@@ -237,7 +233,7 @@ Task("TestNetStandard20EngineCore")
     .OnError(exception => { UnreportedErrors.Add(exception.Message); })
     .Does(() =>
     {
-        RunDotnetNUnitLiteTests(NETCORE_ENGINE_CORE_TESTS, "netcoreapp2.1");
+        RunDotnetNUnitLiteTests(NETCORE_ENGINE_CORE_TESTS, "netcoreapp3.1");
     });
 
 //////////////////////////////////////////////////////////////////////
@@ -302,7 +298,7 @@ Task("TestNetStandard20Engine")
     .OnError(exception => { UnreportedErrors.Add(exception.Message); })
     .Does(() =>
     {
-        RunDotnetNUnitLiteTests(NETCORE_ENGINE_TESTS, "netcoreapp2.1");
+        RunDotnetNUnitLiteTests(NETCORE_ENGINE_TESTS, "netcoreapp3.1");
     });
 
 //////////////////////////////////////////////////////////////////////
diff --git a/cake/package-definitions.cake b/cake/package-definitions.cake
index f8786f0c7..04f431216 100644
--- a/cake/package-definitions.cake
+++ b/cake/package-definitions.cake
@@ -25,32 +25,21 @@ public void InitializePackageDefinitions(ICakeContext context)
         Net40Test,
         Net40X86Test,
         Net35PlusNet40Test,
-        NetCore21Test,
         NetCore31Test,
         Net50Test,
         Net60Test,
-        NetCore21PlusNetCore31Test,
-        NetCore21PlusNetCore31PlusNet50PlusNet60Test,
+        Net50PlusNet60Test,
         Net40PlusNet60Test
     };
 
-    if (dotnetX86Available)
-    {
-        StandardRunnerTests.Add(NetCore21X86Test);
-        StandardRunnerTests.Add(NetCore31X86Test);
-    }
-
     // Tests run for the NETCORE runner package
     var NetCoreRunnerTests = new List<PackageTest>
     {
-        NetCore21Test,
         NetCore31Test,
         Net50Test,
         Net60Test,
         Net70Test,
         Net80Test,
-        NetCore21PlusNetCore31Test,
-        NetCore21PlusNetCore31PlusNet50PlusNet60Test
     };
 
     AllPackages.AddRange(new PackageDefinition[] {
@@ -162,7 +151,6 @@ public void InitializePackageDefinitions(ICakeContext context)
                 HasDirectory("bin/net20").WithFiles(CONSOLE_FILES).AndFiles(ENGINE_FILES).AndFile("nunit3-console.pdb").AndFiles(ENGINE_PDB_FILES),
                 HasDirectory("bin/net35").WithFiles(CONSOLE_FILES).AndFiles(ENGINE_FILES).AndFile("nunit3-console.pdb").AndFiles(ENGINE_PDB_FILES),
                 HasDirectory("bin/netstandard2.0").WithFiles(ENGINE_FILES).AndFiles(ENGINE_PDB_FILES),
-                HasDirectory("bin/netcoreapp2.1").WithFiles(ENGINE_FILES).AndFiles(ENGINE_PDB_FILES),
                 HasDirectory("bin/netcoreapp3.1").WithFiles(ENGINE_CORE_FILES).AndFiles(ENGINE_CORE_PDB_FILES),
                 //HasDirectory("bin/net5.0").WithFiles(ENGINE_FILES).AndFiles(ENGINE_PDB_FILES),
                 HasDirectory("bin/agents/net20").WithFiles(AGENT_FILES).AndFiles(AGENT_PDB_FILES),
diff --git a/cake/package-tests.cake b/cake/package-tests.cake
index 4683be511..26eee6af3 100644
--- a/cake/package-tests.cake
+++ b/cake/package-tests.cake
@@ -72,36 +72,12 @@ static PackageTest NetCore31Test = new PackageTest(
     "netcoreapp3.1/mock-assembly.dll",
     MockAssemblyExpectedResult(1));
 
-static PackageTest NetCore31X86Test = new PackageTest(
-    "NetCore31X86Test",
-    "Run mock-assembly-x86.dll under .NET Core 3.1",
-    "netcoreapp3.1/mock-assembly-x86.dll",
-    MockAssemblyExpectedResult(1));
-
-static PackageTest NetCore21Test = new PackageTest(
-    "NetCore21Test",
-    "Run mock-assembly.dll targeting .NET Core 2.1",
-    "netcoreapp2.1/mock-assembly.dll",
-    MockAssemblyExpectedResult(1));
-
-static PackageTest NetCore21X86Test = new PackageTest(
-    "NetCore21X86Test",
-    "Run mock-assembly-x86.dll under .NET Core 2.1",
-    "netcoreapp2.1/mock-assembly-x86.dll",
-    MockAssemblyExpectedResult(1));
-
-static PackageTest NetCore21PlusNetCore31Test = new PackageTest(
-    "NetCore21PlusNetCore31Test",
-    "Run two copies of mock-assembly together",
-    "netcoreapp2.1/mock-assembly.dll netcoreapp3.1/mock-assembly.dll",
+static PackageTest Net50PlusNet60Test = new PackageTest(
+    "Net50PlusNet60Test",
+    "Run mock-assembly under .NET 5.0 and 6.0 together",
+    "net5.0/mock-assembly.dll net6.0/mock-assembly.dll",//" net7.0/mock-assembly.dll net8.0/mock-assembly.dll",
     MockAssemblyExpectedResult(2));
 
-static PackageTest NetCore21PlusNetCore31PlusNet50PlusNet60Test = new PackageTest(
-    "NetCore21PlusNetCore31PlusNet50PlusNet60Test",
-    "Run four copies of mock-assembly together",
-    "netcoreapp2.1/mock-assembly.dll netcoreapp3.1/mock-assembly.dll net5.0/mock-assembly.dll net6.0/mock-assembly.dll net7.0/mock-assembly.dll net8.0/mock-assembly.dll",
-    MockAssemblyExpectedResult(4));
-
 static PackageTest Net40PlusNet60Test = new PackageTest(
     "Net40PlusNet60Test",
     "Run mock-assembly under .Net Framework 4.0 and .Net 6.0 together",
diff --git a/msi/nunit/engine-files.wxi b/msi/nunit/engine-files.wxi
index eb681e215..6422781b5 100644
--- a/msi/nunit/engine-files.wxi
+++ b/msi/nunit/engine-files.wxi
@@ -94,9 +94,9 @@
             <Component Id="NUNIT_AGENT_NETCORE31" Location="local" Guid="21E39B4C-07E4-4C38-8F91-7030516127E2">
                 <File Id="nunit_agent_netcore31.dll"
                       ProcessorArchitecture="msil"
-                      Source="$(var.InstallImage)bin/agents/netcoreapp3.1/nunit-agent-netcore31.dll" />
+                      Source="$(var.InstallImage)bin/agents/netcoreapp3.1/nunit-agent.dll" />
                 <File Id="nunit_agent_netcore31.dll.config"
-                      Source="$(var.InstallImage)bin/agents/netcoreapp3.1/nunit-agent-netcore31.dll.config" />
+                      Source="$(var.InstallImage)bin/agents/netcoreapp3.1/nunit-agent.dll.config" />
                 <File Id="nunit_agent_netcore31.deps.json"
                       Source="$(var.InstallImage)bin/agents/netcoreapp3.1/nunit-agent.deps.json" />
                 <File Id="nunit_agent_netcore31.runtimeconfig.json"
@@ -122,16 +122,16 @@
             <Component Id="NUNIT_AGENT_NETCORE31_DEPENDENCY_MODEL" Location="local" Guid="6A33A615-BCD2-411C-B3A8-95BF5829C8CA">
                 <File Id="Microsoft.Extensions.DependencyModel.netcore31.dll"
                       ProcessorArchitecture="msil"
-                      Source="$(var.InstallImage)agents/nunit-agent-netcore31/Microsoft.Extensions.DependencyModel.dll" />
+                      Source="$(var.InstallImage)bin/agents/netcoreapp3.1/Microsoft.Extensions.DependencyModel.dll" />
             </Component>
         </ComponentGroup>
         <ComponentGroup Id="NET50_AGENT" Directory="NET50_AGENT_DIR">
             <Component Id="NUNIT_AGENT_NET50" Location="local" Guid="6B5C423E-5EDB-4DD4-8B7F-626C8F4EAF06">
                 <File Id="nunit_agent_net50.dll"
                       ProcessorArchitecture="msil"
-                      Source="$(var.InstallImage)bin/agents/net5.0/nunit-agent-net50.dll" />
+                      Source="$(var.InstallImage)bin/agents/net5.0/nunit-agent.dll" />
                 <File Id="nunit_agent_net50.dll.config"
-                      Source="$(var.InstallImage)bin/agents/net5.0/nunit-agent-net50.dll.config" />
+                      Source="$(var.InstallImage)bin/agents/net5.0/nunit-agent.dll.config" />
                 <File Id="nunit_agent_net50.deps.json"
                       Source="$(var.InstallImage)bin/agents/net5.0/nunit-agent.deps.json" />
                 <File Id="nunit_agent_net50.runtimeconfig.json"
@@ -164,13 +164,13 @@
             <Component Id="NUNIT_AGENT_NET60" Location="local" Guid="8AFA7F03-96EA-4F80-8B79-7AFB59B67786">
                 <File Id="nunit_agent_net60.dll"
                       ProcessorArchitecture="msil"
-                      Source="$(var.InstallImage)bin/net6.0/nunit-agent-net60.dll" />
+                      Source="$(var.InstallImage)bin/agents/net6.0/nunit-agent.dll" />
                 <File Id="nunit_agent_net60.dll.config"
-                      Source="$(var.InstallImage)bin/net6.0/nunit-agent-net60.dll.config" />
+                      Source="$(var.InstallImage)bin/agents/net6.0/nunit-agent.dll.config" />
                 <File Id="nunit_agent_net60.deps.json"
-                      Source="$(var.InstallImage)bin/net6.0/nunit-agent.deps.json" />
+                      Source="$(var.InstallImage)bin/agents/net6.0/nunit-agent.deps.json" />
                 <File Id="nunit_agent_net60.runtimeconfig.json"
-                      Source="$(var.InstallImage)bin/net6.0/nunit-agent.runtimeconfig.json" />
+                      Source="$(var.InstallImage)bin/agents/net6.0/nunit-agent.runtimeconfig.json" />
             </Component>
             <Component Id="NUNIT_AGENT_NET60_ENGINE_API" Location="local" Guid="393F8699-4F44-479B-916D-34F506F089D1">
                 <File Id="nunit.agent.net60.engine.api.dll"
diff --git a/nuget/runners/nunit.console-runner.netcore.nuspec b/nuget/runners/nunit.console-runner.netcore.nuspec
index 4456f8702..3f2860e37 100644
--- a/nuget/runners/nunit.console-runner.netcore.nuspec
+++ b/nuget/runners/nunit.console-runner.netcore.nuspec
@@ -43,7 +43,7 @@
     <file src="net6.0/nunit.engine.api.pdb" target="tools/net6.0/any" />
     <file src="net6.0/nunit.engine.api.xml" target="tools/net6.0/any" />
     <file src="net6.0/testcentric.engine.metadata.dll" target="tools/net6.0/any" />
-    <file src="Microsoft.Extensions.DependencyModel.dll" target="tools/net6.0/any" />
+    <file src="net6.0/Microsoft.Extensions.DependencyModel.dll" target="tools/net6.0/any" />
     <file src="../../nuget/runners/nunit.console.nuget.addins" target="tools/net6.0/any"/>
     <file src="../../nuget/runners/DotnetToolSettings.xml" target="tools/net6.0/any"/>
 
@@ -61,6 +61,7 @@
     <file src="net8.0/nunit.engine.api.pdb" target="tools/net8.0/any" />
     <file src="net8.0/nunit.engine.api.xml" target="tools/net8.0/any" />
     <file src="net8.0/testcentric.engine.metadata.dll" target="tools/net8.0/any" />
+    <file src="net8.0/Microsoft.Extensions.DependencyModel.dll" target="tools/net8.0/any" />
     <file src="../../nuget/runners/nunit.console.nuget.addins" target="tools/net8.0/any"/>
     <file src="../../nuget/runners/DotnetToolSettings.xml" target="tools/net8.0/any"/>
     
diff --git a/src/NUnitEngine/nunit.engine.core.tests/Services/ExtensionManagerTests.cs b/src/NUnitEngine/nunit.engine.core.tests/Services/ExtensionManagerTests.cs
index d0bd6a3f3..86b3b59bc 100644
--- a/src/NUnitEngine/nunit.engine.core.tests/Services/ExtensionManagerTests.cs
+++ b/src/NUnitEngine/nunit.engine.core.tests/Services/ExtensionManagerTests.cs
@@ -153,7 +153,7 @@ public void SkipsGracefullyLoadingOtherFrameworkExtensionAssembly()
             var assemblyName = Path.Combine(GetSiblingDirectory("net35"), "nunit.engine.core.tests.exe");
 #else
             // Attempt to load the .NET Core 2.1 version of the extensions from the .NET 3.5 tests
-            var assemblyName = Path.Combine(GetSiblingDirectory("netcoreapp2.1"), "nunit.engine.core.tests.dll");
+            var assemblyName = Path.Combine(GetSiblingDirectory("netcoreapp3.1"), "nunit.engine.core.tests.dll");
 #endif
             Assert.That(assemblyName, Does.Exist);
             Console.WriteLine($"{assemblyName} does exist");
@@ -242,7 +242,7 @@ public static IEnumerable<TestCaseData> InvalidTargetFrameworkCombos()
             Assembly netFramework = typeof(ExtensionService).Assembly;
 
             var extNetStandard = new ExtensionAssembly(Path.Combine(GetSiblingDirectory("netstandard2.0"), "nunit.engine.dll"), false);
-            var extNetCore = new ExtensionAssembly(Path.Combine(GetSiblingDirectory("netcoreapp2.1"), "nunit.engine.tests.dll"), false);
+            var extNetCore = new ExtensionAssembly(Path.Combine(GetSiblingDirectory("netcoreapp3.1"), "nunit.engine.tests.dll"), false);
 
             yield return new TestCaseData(new FrameworkCombo(netFramework, extNetCore)).SetName("InvalidCombo(.NET Framework, .NET Core)");
 #endif
diff --git a/src/NUnitEngine/nunit.engine.core.tests/nunit.engine.core.tests.csproj b/src/NUnitEngine/nunit.engine.core.tests/nunit.engine.core.tests.csproj
index 388576ee5..676667fde 100644
--- a/src/NUnitEngine/nunit.engine.core.tests/nunit.engine.core.tests.csproj
+++ b/src/NUnitEngine/nunit.engine.core.tests/nunit.engine.core.tests.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <RootNamespace>NUnit.Engine.Core.Tests</RootNamespace>
-    <TargetFrameworks>net35;netcoreapp2.1;netcoreapp3.1;net5.0;net6.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net35;netcoreapp3.1;net5.0;net6.0;net8.0</TargetFrameworks>
     <OutputType>Exe</OutputType>
     <SignAssembly>true</SignAssembly>
     <AssemblyOriginatorKeyFile>..\..\nunit.snk</AssemblyOriginatorKeyFile>
diff --git a/src/NUnitEngine/nunit.engine.core/nunit.engine.core.csproj b/src/NUnitEngine/nunit.engine.core/nunit.engine.core.csproj
index f47de9dfd..b40bd5cb9 100644
--- a/src/NUnitEngine/nunit.engine.core/nunit.engine.core.csproj
+++ b/src/NUnitEngine/nunit.engine.core/nunit.engine.core.csproj
@@ -8,6 +8,7 @@
     <AssemblyOriginatorKeyFile>..\..\nunit.snk</AssemblyOriginatorKeyFile>
     <DebugType>portable</DebugType>
     <DebugSymbols>true</DebugSymbols>
+    <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
   </PropertyGroup>
 
   <PropertyGroup>
diff --git a/src/NUnitEngine/nunit.engine.tests/nunit.engine.tests.csproj b/src/NUnitEngine/nunit.engine.tests/nunit.engine.tests.csproj
index 80b65e858..97e45dd9d 100644
--- a/src/NUnitEngine/nunit.engine.tests/nunit.engine.tests.csproj
+++ b/src/NUnitEngine/nunit.engine.tests/nunit.engine.tests.csproj
@@ -2,7 +2,7 @@
   
   <PropertyGroup>
     <RootNamespace>NUnit.Engine.Tests</RootNamespace>
-    <TargetFrameworks>net35;netcoreapp2.1</TargetFrameworks>
+    <TargetFrameworks>net35;netcoreapp3.1</TargetFrameworks>
     <OutputType>Exe</OutputType>
     <SignAssembly>true</SignAssembly>
     <AssemblyOriginatorKeyFile>..\..\nunit.snk</AssemblyOriginatorKeyFile>
@@ -29,7 +29,7 @@
     <Reference Include="System.Web" />
   </ItemGroup>
   
-  <ItemGroup Condition="'$(TargetFramework)'=='netcoreapp2.1'">
+  <ItemGroup Condition="'$(TargetFramework)'=='netcoreapp3.1'">
     <PackageReference Include="System.ComponentModel.TypeConverter" Version="4.3.0" />
   </ItemGroup>