Symptoms

When using the PDF Converter smart object with webkit enabled option, I’m getting the following error when going to any internal website that doesn't allow anonymous access (from the PDF Converter error log file):

Exceptions:
System.Exception: Conversion error: WebKit Authentication error.
at ExpertPdf.HtmlToPdf.ImgConverter.GetMetafileFromUrlWithWebKit(String url, ᦔ,]and fonts, ᥱand htmlParseInfo)
at ExpertPdf.HtmlToPdf.PdfConverter.ConvertAndGetPdfDocument(String url, String htmlString, String baseUrl, String internalLinksDocUrl, Boolean fromUrl)...
 

Diagnoses

This issue is related to internal IIS site with Kerberos provider configuration, but does not happen with another external site containing both NTLM and Kerberos providers.
 

Resolution

Adding second provider, NTLM resolved the issue.