Blank document after converting doc to pdf

I faced a temporary issue with Aspose Document functionality occurred several weeks ago. We have functionality that fills document(.doc) file with some values and converts the prepared file to pdf. There’re several issues occurred on the whole day(with our different customers) when the file conversion was finished with a blank pdf.
Could you advise what could happen? What are possible reasons why the Aspose Document can behave in such a way?

UPDATED! We are using Aspose.Words for .NET library (18.1.0)
FYI, the issues occurred on November 19-20
We have a valid license for Aspose components

@alexmasalov,

Unfortunately, it is difficult to say what might be the cause of that problem. We suggest you please upgrade to the latest version of Aspose.Words for .NET i.e. 18.12 and see how it goes on your end? Hope, this helps.

In case the problem still remains, please ZIP and upload your input Word document you are getting this problem with and Aspose.Words generated PDF file showing the undesired behavior here for testing. We will then investigate the issue on our end and provide you more information.