We are currently testing an update to 21.3.18.0 from 20.0.81 and we are having this same problem. In our situation, we generate a multipage PDF from HTML source, then loop through the pages and overlay a header and footer onto each page. The distilled code which will reproduce this issue is:

Dim doc As PdfDocument
Dim opt As HtmlToPdfOptions
Dim body, header, footer As String

body = IO.File.ReadAllText("c:\temp\body.html")
header = IO.File.ReadAllText("c:\temp\header.html")
footer = IO.File.ReadAllText("c:\temp\footer.html")

Runtime.AddLicense(*KEY*)

doc = New PdfDocument
HtmlToPdf.ConvertHtml(body, doc)

For i As Integer = 0 To doc.Pages.Count - 1
opt = New HtmlToPdfOptions With {.OutputArea = New RectangleF(0.5, 0.25, 8, 9.5), .MaxLoadWaitTime = 5000}
HtmlToPdf.ConvertHtml(header, doc.Pages(i), opt)

opt = New HtmlToPdfOptions With {.OutputArea = New RectangleF(0.5, 9.9, 8, 1.1), .MaxLoadWaitTime = 5000}
HtmlToPdf.ConvertHtml(footer, doc.Pages(i), opt)

Next

doc.Save("c:\temp\out.pdf")

Not only does calling ConvertHTML in quick succession sometimes generate a timeout error, but sometimes when it doesn't, it simply renders nothing, leaving us a page with no header and/or no footer. In our development environment, we've resorted to adding thread.sleep statements to give the process time to "breathe", but this is not an acceptable solution. It is disheartening to hear the problem is in the most recent version of eo.pdf as well.

I will watch and wait for any response.

Thank you for the quick response. I have downloaded the specific version and tested it again. I ran the test manually 5 times with no timeouts, then put the code in a loop to do 10 at a time to save me some time. The first run I got a timeout error and I have not gotten one since in about 10 runs. I don't know if that one was a fluke, but I will continue to monitor this. For now, this is much better than what we had going.

Thank you again!

To Phil,

We have sent a new build to you through private message. Please let us know if the new build resolves the issue for you.

Thanks!

Great. Thanks for the update! Please feel free to let us know if you run into any other issues.