BUG: Permissions error when you try to debug an ASP.NET Web application in Visual Studio .NET

When you try to debug a Microsoft ASP.NET Web Application project that was created by using the IP address or full computer name for the location, you may receive the following error message:

Using the IP address or full computer name (including the domain) maps the URL to the Internet zone in Microsoft Internet Explorer. If your security settings for the Internet zone are not set to Automatic logon with current username and password, authentication may be unsuccessful and you may receive this error message.

To work around this issue, do one of the following:

• Do not use an IP address or full computer name (for example, computername.domainname.coname.com) when you create your ASP.NET Web Application project. Instead, you can use either "localhost" or the computer name without the domain name (for example, computername).
• Change the security settings for the Internet zone in Internet Explorer to use Automatic logon with current username and password. To do this:
  1. Open Internet Explorer. On the Tools menu, click Internet Options.
  2. On the Security tab, click to select Internet in the list of Web content zones, and then click Custom Level.
  3. Scroll to the bottom of the Settings list. Under User Authentication, locate Logon, and then click to select Automatic logon with current username and password.

Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article.

Steps to Reproduce the Behavior

1. Change the security settings for the Internet zone to use Automatic logon only in Intranet zone. To do this:
   1. Open Internet Explorer. On the Tools menu, click Internet Options.
   2. On the Security tab, click to select Internet in the list of Web content zones, and then click Custom Level.
   3. Scroll to the bottom of the Settings list. Under User Authentication, locate Logon, and then click to select Automatic logon only in Intranet zone.
2. In Visual Studio .NET, create a new Visual C# ASP.NET Web Application project by using the IP address of your server computer (for example, http://xxx.xxx.xxx.xxx/Webapplication1).
3. Press F5 to start debugging.

For additional information, click the article numbers below to view the articles in the Microsoft Knowledge Base: