Hee Soo: Since it’s not possible to get two different Status Codes in one response, perhaps what you’re seeing is that the page is returning the 404 page correctly, but with a 200 Status response. In that case, there could be a problem with your application overriding the IIS Setting (and this could take lots of different forms), the status code in the IIS setting being incorrect (such as if you used specific 404 code like 404.2 instead of just 404), or there could be another setting that is incorrect. We hope that helps!

Bjorgen: Thanks for contacting us. To prevent the custom 404 error page from being indexed in search engines, the page should have a meta robots=”noindex” instruction. As for being “accessed directly by clients,” the page is meant to be seen by anyone attempting to access a nonexistent URL. As for your server question, I will check with our technical team and update this comment.

UPDATE: Our procedure in this post does not mention using “Server.GetLastError()” at all. Per our technical team, there are lots of reasons why that function may return no data.