Here’s a helpful hint, in case you run into a problem trying to enlist an orchestration. If you run into an error while enlisting an orchestration after deploying it to the server, you might want to consider if you followed the proper steps to deploy the orchestration. Common knowledge is to ensure that the proper assembly is available in the GAC upon the server you deployed the BizTalk orchestration to. In addition, make sure all the assemblies that the BizTalk assembly uses are also available in the GAC as well.
If this isn’t the case, you could run into the following exception:
Exception type: BTXEnlistmentException
“NullReferenceException exception occurred while the XLANG/s runtime enlisted a service.”
Just make sure you include a script to GAC the DLL into the assembly and you will be able to proceed.