In a notable shift during the recent Patch Tuesday, Microsoft has introduced a feature that mandates unique Security Identifiers (SIDs) across systems. This change has stirred the waters for those who have relied on cloning images onto multiple machines within their networks. Users who have previously enjoyed the convenience of duplicate SIDs for Kerberos or NTLM connections may find themselves grappling with issues since August 29, 2025.
For many, the aftermath of this update has manifested in the form of SECENO_CREDENTIALS errors appearing in the Event Viewer, alongside a host of other errors reported on platforms like Bleeping Computer. The message from Microsoft is clear: the use of duplicate SIDs is no longer acceptable. Instead, they advocate for a fresh setup of machines utilizing the Sysprep tool.
For those hesitant to embrace this new protocol, there exists a workaround. A Group Policy setting can be deployed to permit machines to operate with duplicate SIDs. However, this option comes with its own set of challenges. Users must contact Microsoft support to request access to this setting, as it is not readily available in the Group Policy Object (GPO) by default.
This recent development marks the third instance of authentication errors linked to Microsoft updates, a trend that has raised eyebrows among industry observers. As the landscape evolves, organizations will need to navigate these changes with care, ensuring compliance while maintaining operational efficiency.
