asp.net - Entity Framework : "The underlying provider failed on Open" -

When I try to insert a record, then I get the error: The underlying provider failed on Open. This error occurs only with IIS and not with the VWD 2008 webserver. In EventViewer I application error: Failed to generate a user instance of SQL Server due to failure to begin the process for the user instance. The connection will be closed. [Client:]

  & lt; Add name = "Aspianiteedibiintitij" connection string = "metadata = Ridge: // * / Modlskfriand list. Csdl | res: // * / model .FriendList.ssdl | res: //*/Models.FriendList.msl; Provider = SystemkDatakSqlClient; provider connection string = & amp; quot; data source =. \ SQLEXPRESS; AttachDbFilename = | DataDirectory | \ ASPNETDB.MDF; integrated Security = true; connect timeout = 30; user instance = true; Akadikaktivarsltsets = True & amp; quot; "Provider Name =" System.Data.EntityClient "/>  

I am using the aspnetdb.mdf file, and not from an external database. I have done enough research for this but it has no use.

everything just works fine with VWD webserver

< p> If you try to log on with the identification being used to run the application by using the current integrated authentication to access the web server aspnetdb database should make your SQL account (web server ).

The examples below use the integrated certificate. I would however use SQL auth.