After some research, here is what specifically causes the problem. The post from KnightOfNi at this thread: forums.msdn.microsoft.com/.../ is fundamentally correct, however, as in my client’s case, even after setting ADAM back on to the domain password policy, the same error  still happens. The cause is that either no password expiration policy has been set or the policy is that the password does not expire. In Active Directory, this means setting the Password Expiration to 0 days. Definitely not a Microsoft best practice, but something mandated by my client’s senior management. The web  part will work once the password expiration has been set. AD Password policy can only set at the domain level. You can set it elsewhere but it’s not going to have any (or in the case of computers...machine settings, little) effect. The ECTS looks for the first domain policy and checks its settings. That’s why if no Domain password expiration policy has been set or set to 0 days it will fail with the error message shown in the previous postings.