Problems with updating asp .net (vb) web app

Hi i just update an old webapp and now i have this error

Error 10 Type 'System.Web.Security.MembershipUser' in assembly 'System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' has been forwarded to assembly 'System.Web.ApplicationServices'. Either a reference to 'System.Web.ApplicationServices' is missing from your project or the type 'System.Web.Security.MembershipUser' is missing from assembly 'System.Web.ApplicationServices'. E:\PC\Visual Studio 2010\Projects\TIVENCA\Fuente\Tivenca 10-12-2008\Mega.TimeCard.Web\Cargar\Cargar.aspx.vb 89 27 E:...\Mega.TimeCard.Web\

Here is the line

Dim mu As MembershipUser = Membership.GetUser(Profile.UserName)