From: John Bell on
On Sat, 27 Mar 2010 11:18:56 -0400, Harlan Messinger
<h.usenetremoverthis(a)> wrote:

>I'm using Visual Studio 2008 and SQL Server Express 2008. I've built the
>beginnings of an ASP.NET 3.5 app that reads a connection string from the
>configuration, in the usual way, and I can use LINQ-to-SQL against it
>and output listings of data from the database to a page with no problem.
>But I've created a custom membership provider that uses this string to
>create a data context for LINQ-to-SQL, and placed a Login control on a
>page that uses this membership provider. This page opens fine when I run
>it from Visual Studio, but when I enter some text into the login form
>and submit it, the error message "Failed to generate a user instance of
>SQL Server. Only an integrated connection can generate a user instance."
>appears in the browser. Visual Studio, meanwhile, doesn't give me any
>indication that there's a problem. The details under the error message
>in the browser go on about the App_Data directory, but my App_Data
>directory is empty and I haven't referred to it anywhere.
>Any ideas on the source of the trouble?


The error suggests that you don't have Integrated Security=True in the
connection string, but I would expect that you would get that from
visual studio if it was the case.If you are using a forms based
authentication I would expect that you are trying to enter as username
and password for the connection i.e. SQL Server authentication, in
which case you can create a user instance.