After following the steps outlined in my previous post, Active Directory Module Localhost Setup, you may still have issues trying to use the Active Directory module LDAP features. When I reported this to Sitecore Support, they acknowledged it as a bug and provided the following explanation and fix. The fix they suggested below resolved my issue. The updated DLL is attached, Sitecore.Support.403947.dll.
Sitecore CMS 7.2
7.2 rev. 140314
Active Directory Module
1.1 rev. 130705
We were able to reproduce a similar issue and have registered an appropriate bug report.We found that the AuthenticationManager API cannot login users to back-end. The method Sitecore.Security.Authentication.AuthenticationManager.Login is used in the ldaplogin page for AD, so that’s why the signle sign-on doesn’t work.I suppose that the problem is that the new security implementation has more strict rules for a current authentication ticket. However the AuthenticationManager doesn’t create this necessary ticket and cookie values so it cannot login users to back-end.Also it should work fine for a front-end implementation.Meanwhile as a workaround could you please try the following patch:1. Put the attached Sitecore.Support.403947 assembly to your bin folder.2. Change the Inherits class in the Website\sitecore\admin\ldaplogin.aspx file like:<%@ Page Language=”C#” AutoEventWireup=”true” Inherits=”LightLDAP.Support.LDAPLogin” %>