Document generation API throws error for simple docx to PDF conversion with JSON data

Hi,
I have a simple docx document with just two tags {{Year}} and {{ReturnBy}}. When I pass JSON data to the DocumentMergeOperation and execute from .net SDK, getting the following exception.

Adobe.PDFServicesSDK.exception.ServiceApiException: 'The input file appears to be corrupted and cannot be processed.; requestId=16db0c7b-c759-4d86-9a0a-fb93ccfeb303'

I have attached the docx file for your reference. Below is the JSON data.

{"Year":"2024", "ReturnBy":"January 30, 2024"}

I have followed the .net SDK documentation https://developer.adobe.com/document-services/docs/overview/document-generation-api/gettingstarted/#generate-pdf-or-word-document