I'm using a recent version of the product: 18.1.31.0

I have a service which converts pages from another server into pdfs on a somewhat regular basis using the HtmlToPdf.ConvertUrl method. A few times, this service has started failing, with exception messsage:

This WebView either has already been destroyed or is being destroyed.

After that, every subsequent call to the method is failing with the same error, until the process is restarted. Unfortunately, this seems to be random and rare and I haven't been able to catch it in a controlled environment. I don't even have a stack track right now, our log is throwing it away.

Ideally, I'd like to have a way to get the service back to normal without having to restart. Might I need to rewrite this to use something other than HtmlToPdf.ConvertUrl so I can get at the underlying WebView/Engine objects?

Thanks for the reply. In previous threads on the topic of this error, I believe support recommended handling an event on the WebView to get more detailed information about why it was closed. I wonder if this might help me reproduce the issue. How do I get at the underlying WebView object?

It seems like to do what we're talking about, I would have to replace calls to HtmlToPdf.ConvertUrl with something like

using (var session = HtmlToPdfSession.Create())
{
session.LoadUrl(url);
session.RenderAsPDF(doc);
}

Is this correct?

So, I've replaced our call to HtmlToPdf.ConvertUrl(string url, PdfDocument doc, HtmlToPdfOptions options) with the below method, in order to try and capture any extra information when the problem occurs:

using (var session = HtmlToPdfSession.Create(options))
{
session.RunWebViewCallback((view, args) =>
{
view.LoadFailed -= LoadFailedCallback;
view.LoadFailed += LoadFailedCallback;
view.Closed -= ViewClosedCallback;
view.Closed += ViewClosedCallback;
view.RenderUnresponsive -= RenderUnresponsiveCallback;
view.RenderUnresponsive += RenderUnresponsiveCallback;
return null;
}, null);
session.LoadUrl(url);
session.RenderAsPDF(doc);
}

One thing I've noticed is, when I use the above code in a console application, the WebView.Closed callback is executed as soon as the application stops running, with reason WebViewCloseReason.Normal. In my actual service, which runs on IIS, nothing has so far been logged from this callback, even when IIS is reset or application pool recycled. Another event, WebView.LoadCompleted, is firing as I would expect. Is this normal and, if not, could it be related to my problem? Also, are there any other events I could be hooking into to get more information?

I'd like to be able to reproduce the issue, but I think that will be infeasible without more information (it's only happened 3 times, among many thousands of conversions). I have no evidence that the error is due to a bad response from the url being converted, and I suspect it only occurs after my service has been active for a while. Do you have any suggestions for an approach to reproducing the problem?