When using the Password Change Web Part (Bamboo Password Change Web Part), users receive the following error message when they click ChangePassword:
Unable to change password. Password does not meet the minimum policy requirements.
It is important to note that the Password Change Web Part does not determine if the new password complies with the domain's Password Policy. The web part makes the password change call to Active Directory, and it is then AD that determines if the policy is met or not, and the web part shows the response from AD.
Re-examine the AD domain's Password Policy to determine which setting(s) the new password is failing. (A common failure is not meeting the "Enforce password history" setting, but of course, any other Password Policy setting may also be causing the error.)
If you want confirmation that AD is failing the new password (and not the web part), go to a Windows machine on the domain's network and use Ctrl-Alt-Del, then select the "Change a password..." option. Enter the same details here that were entered on the web part interface, including the new passwordthat failed when using the web part. An error similar to the web part's displayed error will result.
Please also note that resetting a user's password directly in AD is not a sufficient test for this issue, since a password 'reset' is not the same as a password'change'.