Can anyone help me get past this Service Fabric cluster build error?

Hi,

I have not been able to figure out which value it refers to being null.

This is the error message when debugging the solution.

"Severity Code Description Project File Line Suppression State
Error MSB4018 The "GetServiceProjectReferences" task failed unexpectedly.
System.ArgumentNullException: Value cannot be null.
Parameter name: source
at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable1 source, Func2 predicate)
at Microsoft.VisualStudio.Azure.Fabric.BuildTasks.ServiceModelServiceSlim.GetPrimaryCodePackage(ServiceManifestSlim serviceManifest)
at Microsoft.VisualStudio.Azure.Fabric.BuildTasks.GetServiceProjectReferences.SetMetadataForProjectReferences(PackageBehaviorOptions packageBehavior)
at Microsoft.VisualStudio.Azure.Fabric.BuildTasks.GetServiceProjectReferences.Execute()
at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()
at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__26.MoveNext() ApplicationName C:\Users\xxx\xxx\packages\Microsoft.VisualStudio.Azure.Fabric.MSBuild.1.7.1\build\Microsoft.VisualStudio.Azure.Fabric.Application.targets 106"

It refers to this line:

<GetServiceProjectReferences ProjectReferences="@(ProjectReference)"
ProjectReferencesWithConfiguration="@(ProjectReferenceWithConfiguration)"
ServicePackageRootFolder="$(ServicePackageRootFolder)"
ApplicationManifestPath="$(ApplicationManifestFilePath)"
IncludeInPackagePaths="@(IncludeInPackagePaths)"
PackageBehavior="$(PackageBehavior)"
Configuration="$(Configuration)">

Any suggestion appreciated. I've hit a complete halt and am still learning basic stuff.

Thanks,
El