I am trying to use ABCpdf .NET with Azure App Service and getting the following error when generating a PDF.
Unable to render HTML. Failed to configure IE 9
You cannot modify the registry with Azure Web Apps (formerly Web Sites). So, you're getting an error because the app cannot register itself. Being a multi-tenant service, you are not allowed to make registry modifications.
You need to go back and look at that page again, where they suggest using a VM or a web/worker role (both of which do allow for registry modification).