Unit Testing Unity Configuration File "The type name or alias xxxx could not be resolved"

I want a simple unit test to verify that all Types in my unity configuration xml are valid

[TestMethod]
[TestCategory("IntegrationTest")]
[DeploymentItem(@"..\..\..\App\Unity.config", @"MyApp")]
public void VerifyTypeNamesForMyAppUnityConfig()
{       
   var fileMap = new ExeConfigurationFileMap { 
      ExeConfigFilename = @"MyApp\Unity.config" 
   };
   var configuration = ConfigurationManager
       .OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None);
   var unitySection = (UnityConfigurationSection)configuration.GetSection("unity");
   var container = new UnityContainer();

   container.LoadConfiguration(unitySection);
}

The Unity.config works when executing the App.

I have referenced all the assemblies in the Test project

I get this exception

Test Name:  VerifyTypeNamesForMyAppUnityConfig
Test FullName:  MyApp.Test.UnityTests.VerifyTypeNamesForMyAppUnityConfig
Test Source:    c:\SourceControl\MyAppMerge\MyApp.Test\UnityTests.cs : line 47
Test Outcome:   Failed
Test Duration:  0:00:00.5187389

Result Message: 
Test method MyApp.Test.UnityTests.VerifyTypeNamesForMyAppUnityConfig threw exception: 
System.InvalidOperationException: The type name or alias MyApp.Services.Attachments.AttachmentService, MyApp.Services.Attachments could not be resolved. Please check your configuration file and verify this type name.
Result StackTrace:  
at Microsoft.Practices.Unity.Configuration.ConfigurationHelpers.TypeResolverImpl.ResolveType(String typeNameOrAlias, Boolean throwIfResolveFails)
   at Microsoft.Practices.Unity.Configuration.RegisterElement.GetMappedType()
   at Microsoft.Practices.Unity.Configuration.RegisterElement.ConfigureContainer(IUnityContainer container)
   at Microsoft.Practices.Unity.Configuration.ContainerElement.<>c__DisplayClass1.<ConfigureContainer>b__0(ContainerConfiguringElement element)
   at Microsoft.Practices.ObjectBuilder2.EnumerableExtensions.ForEach[TItem](IEnumerable`1 sequence, Action`1 action)
   at Microsoft.Practices.Unity.Configuration.ContainerElement.ConfigureContainer(IUnityContainer container)
   at Microsoft.Practices.Unity.Configuration.UnityConfigurationSection.Configure(IUnityContainer container, String configuredContainerName)
   at Microsoft.Practices.Unity.Configuration.UnityContainerExtensions.LoadConfiguration(IUnityContainer container, UnityConfigurationSection section, String containerName)
   at Microsoft.Practices.Unity.Configuration.UnityContainerExtensions.LoadConfiguration(IUnityContainer container, UnityConfigurationSection section)
   at MyApp.Test.UnityTests.VerifyTypeNamesForMyAppUnityConfig() in c:\SourceControl\MyAppMerge\MyApp.Test\UnityTests.cs:line 61

The test PASSES If I make this change

var WTF = new List<AttachmentService>();
container.LoadConfiguration(unitySection);

But this FAILS like this

//var WTF = new List<AttachmentService>();
container.LoadConfiguration(unitySection);

WHY?