Unhandled Exception: System.ArgumentOutOfRangeException: Non-negative number required.
Parameter name: value
   at System.IO.FileStream.set_Position(Int64 value)
   at PdfSharp.Pdf.IO.Lexer.ReadRawString(Int32 position, Int32 length)
   at PdfSharp.Pdf.IO.Parser.ReadTrailer()
   at PdfSharp.Pdf.IO.PdfReader.Open(Stream stream, String password, PdfDocumentOpenMode openmode, PdfPasswordProvider passwordProvider)
   at PdfSharp.Pdf.IO.PdfReader.Open(String path, String password, PdfDocumentOpenMode openmode, PdfPasswordProvider provider)
   at PdfSharp.Pdf.IO.PdfReader.Open(String path)