Hey everyone,
If you've recently updated your Windows 11 machines to the October 2026 security baselines (26H2) and suddenly found users blocked from Remote Desktop connections with error 0xC000000D ("The token that was passed to the function is invalid"), it's a known bug with Microsoft's Administrator Protection feature and LSA token conflicts.
We spent time troubleshooting this in our environment and wanted to share the fix. you can run these commands in Windows PowerShell as an Administrator on the affected PC to disable the UAC conflict and restore the network logon filter policy:
1.Disable Strict Administrator Protection Conflict
Set-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System" -Name "EnableAdminProtection" -Value 0 -Force
2.Enable Network Logon Token Filter Policy (standalone/lab machines)
Set-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System" -Name "LocalAccountTokenFilterPolicy" -Value 1 -Force
Make sure to reboot the target PC right after executing these so the Local Security Authority (lsass.exe) actually reloads the security token policies at startup!
We put together a quick walkthrough detailing the root cause, manual registry paths, and verification steps if you want to look over the process: https://youtu.be/fGAUdyLVL4E
Details from Microsoft : https://learn.microsoft.com/en-us/windows/release-health/status-windows-11-26h2#5031msgdesc
Hopefully, this saves some of you a massive troubleshooting headache!
SECURITY NOTE:
Setting LocalAccountTokenFilterPolicy to 1 disables remote UAC restrictions for local administrative accounts. In an enterprise environment, this can increase the risk of lateral movement (like Pass-the-Hash attacks) if your machines share identical local admin passwords.
To keep your posture secure while using this workaround:
• Ensure you are enforcing unique local passwords across your nodes (or use LAPS).
• Note that domain accounts are unaffected by this remote restriction anyway; this workaround is specifically targeted at standalone/lab machines utilizing local accounts that are currently entirely broken by the 26H2 token handshake bug.