I have tried two HTML to Image conversion packages HiQPd and NReco.
Both libraries work beautifully when run from Visual Studio on my local PC.
When I deploy to an Azure-hosted website, both packages fail thusly:
The HTML I'm converting is simple stuff, like <p>Hello</p>
Is this a problem with Azure, hosting on servers in general, or not including some library which "everybody knows that!"?
Upgrading my Azure service plan to B1 Basic solved my problem. Thank you Vitaliy!