Here’s web-systems based error that is tangentially related to BizTalk 2006. If you use BizTalk 2006 in order to generate a webservice this problem will often need to be fixed before your webservice will be useable.
This issue is that you receive the above error message, Unrecognized attribute ‘xmlns’., when you attempt to log on a webservice and use it. It’s easy to test for as it should show up if you use a browser to hit the service and attempt to load up the test forms.
This is caused because, although the web service/web page is using Asp .Net 2.x, the website itself is set to use Asp .Net 1.x
The trick is simply the launch the IIS management application, navigate to the Asp .Net tab, and set the target framework to the 2.x version of the framework.
Try again and hopefully, it should work.