Thank you for contacting us with your question.
Windows 7 has an additional security feature called Extended Protection. When you create an app.config for a client from the Windows 7 service, the tag "extendedProtectionPolicy" will be present in the app.config. When deploying the client to versions of Windows prior to Windows 7, this tag will not be valid. This is a known issue. This tag is not actually used by the client, so simply remove the tag. We will try to update future versions of .Net 3.5 to not include this tag in the generated app.config.
Thanks,
WCF Team
由 Microsoft 在 2009/7/16 10:11 发送