Password rotation: Error changing (replace) attribute 'unicodePwd'.: 53 - Server is unwilling to perform

Troubleshooting
1

If this error is displayed for only one credential using the LDAP template for password rotation, proceed with the guidance below.

Possibly, this credential is part of a password policy and/or GPO that requires more characters for the previously configured password strength.

1. Adjust the character number to a higher number.

2. Increase the number of digits in the strengthened password and uppercase letters."

2

Another option, in case your policy in Segura® matches with AD GPO, is to check if you are not using a secure connection (SSL/TLS).
Active Directory strictly forbids changing or resetting passwords over unencrypted plaintext connections. Take a look at your Domain Controller in Devices page by editing and adding LDAPS (port 636) to it under Connectivity tab.