Hi,
You have a message instance that is not initialized in a Message Assignment shape in your orchestration. Your error description pretty much points that out:
“Shape name: Construct Date…
Exception thrown from: segment 1, progress 58
Inner exception: Object reference not set to an instance of an object.
Exception type: NullReferenceException
Source: Microsoft.XLANGs.Engine”
Instantiate your message properly and that should fix your problem.
Daniel.