We are using EO.PDF version 15.4.5.0 to convert HTML content to PDF in .NET environment. Recently we started getting below mentioned exception every day for all the PDF Conversions. It's screwing up the whole business. This PDF generation is done by a Windows Service.

When we restart Windows Service, it is working fine for some time and the issue comes back. We are not sure about this issue. Can you please assist us on this issue?

Type : EO.Pdf.HtmlToPdfException, EO.Pdf, Version=15.4.5.0, Culture=neutral, PublicKeyToken=e92353a6bf73fffc
Message : Conversion failed. Failed to initialize conversion (2).
Source : EO.Pdf
Help link :
ErrorCode : 0
Data : System.Collections.ListDictionaryInternal
TargetSite : EO.Internal.aiu a(EO.Internal.abb, EO.Internal.a46)
HResult : -2146233088
Class Name: EO.Internal.aiu
Stack Trace : at EO.Internal.aiu.a(abb A_0, a46 A_1)
at EO.Pdf.HtmlToPdfSession..ctor(HtmlToPdfOptions A_0)
at EO.Pdf.HtmlToPdf.ConvertHtml(String html, PdfDocument doc, HtmlToPdfOptions options)
at EO.Pdf.HtmlToPdf.ConvertHtml(String html, Stream stream, HtmlToPdfOptions options)
at RMS.Utilities.Utils.GeneratePDFDocument(String contents, Vehicle vehicle, Int32 userID, Int32 buyerID, Int32 documentTypeID, String EOLicense)

Type : EO.Internal.qg, EO.Pdf, Version=15.4.5.0, Culture=neutral, PublicKeyToken=e92353a6bf73fffc
Message : Failed to initialize conversion (2).
Source : EO.Pdf
Help link :
Data : System.Collections.ListDictionaryInternal
TargetSite : Void a(EO.Internal.aiu, EO.Internal.ald)
HResult : -2146233088
Class Name: EO.Internal.aiu
Stack Trace : at EO.Internal.aiu.a(aiu A_0, ald A_1)
at EO.Internal.aiu.a(abb A_0, Boolean A_1, a46 A_2)
at EO.Internal.aiu.a(abb A_0, a46 A_1)