Windows Update Fiasco: Duplicate SIDs Cause Authentication Chaos!
Microsoft confirmed that Windows updates since August 29, 2025, are causing authentication issues on systems sharing Security Identifiers (SIDs). This change, designed to enforce SID uniqueness, leads to failures in Kerberos and NTLM authentication, resulting in “access denied” errors and failed logins. Rebuilding systems or special Group Policy configurations can temporarily alleviate the chaos.
Hot Take:
Oh, Microsoft, you’ve done it again! Just when we thought our Windows systems were as secure as Fort Knox, you drop another update that leaves us all locked out of our own digital homes. It seems like the ghost of duplicate SIDs is here to haunt us, and those authentication failures are more terrifying than any Halloween jump scare. But hey, at least it’s a great excuse to avoid those pesky remote meetings!
Key Points:
- Windows updates from August 29, 2025, are causing authentication failures due to duplicate Security Identifiers (SIDs).
- These failures impact Windows 11 24H2, Windows 11 25H2, and Windows Server 2025 users.
- Issues include failed remote desktop connections and “access denied” errors due to SID duplication.
- Duplicate SIDs often result from improper system cloning without using the Sysprep tool.
- Microsoft suggests systems be rebuilt or a special Group Policy be configured as a temporary fix.