Question

I’m writing a console application, that uses SharePoint object model to manipulate data inside of SharePoint.

There are two variables:

SPWeb spWeb
string formsUser   //username

and I’m trying to resolve user

SPUser userF = spWeb.EnsureUser(formsUser);

This line keeps throwing exception:

Could not load file or assembly “System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35” or one of its dependencies. The system cannot find the specified file.

My project’s Target framework is .Net Framework 3.5. I have reference to System.Web.Extensions.dll, version 3.5.0.0..

What I cannot understand:

1. Why is my application expecting this assembly in version 4.0.0.0 and not in 3.5.0.0 ?
2. Why this line would be throwing exception regarding System.Web.Extensions, if everything in this line is about Microsoft.SharePoint assembly

Update:
in above example I’m using forms based user, so the string is something like: i:0#.f|someprovider|john.doe. If I use Windows based user instead, so i:0#.w|domain\john.doe, this exception is not thrown.

Is there any chance, that SPUser is secretly trying to use System.Web.Extensions, and fails?

Answer 1

I found solution:

The app.config file in my application contains system.web/membership and roleManager sections. And there was reference to the System.Web.Extensions, Version=4.0.0.0

<add name="ClientAuthenticationMembershipProvider" 
     type="System.Web.ClientServices.Providers.ClientFormsAuthenticationMembershipProvider, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />