IIS Windows Authentication issue in Silverlight 4

Question

Wondering if anyone has encountered this authentication issue? My web server is running IIS7 on a Windows Server 2008 machine and the .NET 4.0 runtime. The virtual directory for my application has ASP.NET impersonation and Windows authentication turned on. Anonymous, Basic, Digest and Forms Authentication are turned off.

"There was a failure using the default 'ProfileProvider'. Please make sure it is configured correctly. Failed to generate an instance of SQL Server due to a failure in starting the process for the user instance. The connection will be closed."

Due to this error, my Silverlight 4 application is unable to retrieve the current user's windows loginid information. The error does not happen locally on my dev machine, but only out on the deployed IIS server. I have fiddled with the roleManager config value and tried setting it to true and commenting out the whole entry, but I'm still seeing the same error message.

Hoping someone out there has come across this error and a solution/explanation for what's causing it to happen.

thanks in advance, John

Here are my current web.config authentication and role settings. (angle brackets omitted)

roleManager enabled="false"
identity impersonate="true"
authentication mode="Windows"

Answer 1

After a lot of experimentation and googling, turns out that there was a profile section in my web.config file.

<profile enabled="false">
  <properties>
    <add name="FriendlyName" />
  </properties>
</profile>

I needed to add enabled="false" to the profile tag to turn off any default ProfileProvider functionality to the site.

Why it isn't set to false, by default, is beyond me.