I’m working on a project where I’m trying to build an automated regression testing tool for my AJAX library. I’m using the HttpWebRequest object to automate the HTTP calls to the web server.

I started encountering a problem where I was getting HTTP 417 (expectation failed) error messages, which I couldn’t seem to resolve, until I found this fix over on the MSDN forums.

All you have to do is add the following into your application configuration file:

<configuration>
<system.net>
<settings>
<servicePointManager expect100Continue=”false” />
</settings>
</system.net>
</configuration>

That resolved the errors for me… now to figure out what is wrong with cookies…