Anyone can resolve this error. I didn't get the reason why this error occur. I coding according to instruction to generate pdf from URL.
Here is my code below in Vb.net.
Dim client As New pdfcrowd.Client("asdasd", "02fasdaasdacfsdadc1764easda01cd2f2c1")
' convert a web page and write the generated PDF to a memory stream
Dim Stream As New MemoryStream
client.convertURI("http://localhost:881/print/mypage/125", Stream) //Here I'm getting error, error detail you can found in attachment.
' set HTTP response headers
Response.AddHeader("Content-Disposition", "attachment; filename=" & name& ".pdf")
' send the generated PDF