You receive a "Proxy authentication required" error message when you try to use Visual Studio 2005 online features (910804)

WORKAROUND

To work around this issue, use one of the following methods.

Method 1: Modify the Visual Studio 2005 configuration file

If the proxy server uses Windows authentication, the Visual Studio 2005 Help system cannot provide Windows credentials to the proxy server. You can modify the Visual Studio 2005 configuration file to work around this issue. When you do this, the Visual Studio 2005 Start Page is not affected, and this page downloads content correctly.

To make Visual Studio 2005 provide Windows credentials to the proxy server, either replace the code in the configuration file with the following code, or add the code starting with the <defaultProxy> tag and ending with the </defaultProxy> tag to the configuration file.

<configuration>
    <startup>
        <supportedRuntime version="v2.0.50727" safemode="true"/>
        <requiredRuntime version="v2.0.50727" safemode="true"/>
    </startup>
    <runtime>
        <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
            <probing privatePath="PublicAssemblies;PrivateAssemblies"/>
            <dependentAssembly>
                <assemblyIdentity name="EnvDTE" publicKeyToken="b03f5f7f11d50a3a" culture="neutral"/>
                <bindingRedirect oldVersion="7.0.3300.0" newVersion="8.0.0.0"/>
            </dependentAssembly>
        </assemblyBinding>
    </runtime>
    <system.net>
        <settings>
            <ipv6 enabled="true" />
        </settings>
        <defaultProxy enabled="true" useDefaultCredentials="true">
            <proxy bypassonlocal="True" proxyaddress="http://yourproxy"/>
        </defaultProxy>
    </system.net>
</configuration>

Notes

• You must insert the correct proxy server address for your network in the following line of code:

  proxy bypassonlocal="True" proxyaddress="http://yourproxy:port#"/

• The configuration file has the following file name:

  Drive:\Program Files\Common Files\Microsoft Shared\Help 8\Dexplore.exe.config

• If you use the integrated Help viewer, you must add the XML code to the configuration file. The configuration file has the following file name:

  Drive:\Program Files\Microsoft Visual Studio 8\Common7\IDE\Devenv.exe.config

Method 2: Use the integrated Web browser in Visual Studio 2005

In certain cases, the proxy server may use another authentication scheme, such as LDAP-based authentication on a UNIX box. However, there is no guaranteed way to make the Visual Studio 2005 Help system provide the needed credentials to the proxy server. The Visual Studio 2005 client must be designed to prompt the user for credentials when the proxy server requests credentials. However, this prompting mechanism does not exist in Visual Studio 2005.

You may be able to work around this issue by using the integrated Web browser in Visual Studio 2005. To do this, follow these steps:

1. Start Visual Studio 2005.
2. On the View menu, point to Other Windows, and then click Web Browser.
   
   An authentication message may appear when the integrated Web browser tries to access a Web site. If you are prompted for authentication credentials, go to step 3.
3. Enter a valid username and password.
   
   The Visual Studio 2005 Start Page and Visual Studio 2005 online Help may now function correctly.