FHIR to HL7v2 internal server error

[mklierman]

I'm attempting to use the sample template, ObservationBundle, to convert from FHIR to Hl7v2 and I'm getting a 500 internal server error. I'm able to convert from Hl7v2 to FHIR and JSON to FHIR without issues.

The application log shows:
Failed conversion request with HTTP Status 500 InternalServerError; TOP-LEVEL-ERROR: InternalServerError - Encountered an unexpected service error.; INNER ERROR: Code: TemplateRenderFailed, Message: 'An unexpected error was encountered while rendering the template: Error happened when rendering templates: Object reference not set to an instance of an object..', Exception: TemplateException; InnerException: RenderException - Code: TemplateRenderingError, Message: 'Error happened when rendering templates: Object reference not set to an instance of an object.'

This happens even if I use an empty input string like so:

{ "InputDataFormat": "Fhir", "RootTemplateName": "ObservationBundle", "InputDataString": "{} }