The specified LINQ expression contains references to queries that are associated with different contexts.

Hi Guys i am getting below error

The specified LINQ expression contains references to queries that are associated with different contexts.

 UserManager manager = new UserManager();
        RoleManager rolemanager = new RoleManager();

        var usersinrole = from u in manager.Users
                          from ur in u.Roles join r in rolemanager.Roles on ur.RoleId equals r.Id
                          select new
                          {
                              u.Id,
                              Name = u.UserName,
                              Role = r.Name
                          };

        var userList = usersinrole.ToList();

   
        GridView1.DataSource = userList;
        GridView1.DataBind();

Could anybody let me know where i am wrong 

Thanks,

Shabbir