Fix STATUS_LOCAL_USER_SESSION_KEY 0X40000006

What's Actually Happening Here

You're seeing error 0X40000006 (STATUS_LOCAL_USER_SESSION_KEY) when trying to access a network share, map a drive, or connect to a domain resource. Windows 10 22H2 and Windows 11 23H2 users hit this most often after a password change, domain migration, or waking from sleep.

The root cause: your local workstation cached a Kerberos session key that no longer matches what the domain controller expects. It's like showing an expired badge at a secure door — the system rejects it immediately. The error is specific to Kerberos, not NTLM, so it only shows up in domain environments.

Quick Fix (30 seconds): Flush Kerberos Tickets

This wipes out the stale session key and forces a fresh authentication. No reboot needed.

Open Command Prompt as Administrator. Hit Start, type cmd, right-click, choose Run as administrator.
Run:
```
klist purge
```
Enter Y when it asks to purge all tickets.
Close the prompt and try accessing your network share again.

Why this works: klist purge deletes the local Kerberos ticket cache. Your next connection attempt will request a fresh ticket from the domain controller, which includes the correct session key. What's actually happening here is the old ticket had a session key encrypted with your old password hash — after a password change, that key fails verification. Purging removes the bad ticket entirely.

If it still fails, move on. This clears the cache but won't fix a corrupted trust relationship.

Moderate Fix (5 minutes): Log Off and Back On

If the quick flush didn't help, your user profile likely cached a bad credential set that blocks re-authentication each time.

Save any open work.
Sign out of Windows: Start menu → your profile picture → Sign out.
Wait 10 seconds, then sign back in.
Try the network resource again.

Why this works: When you log off, Windows drops the user session, including all cached Kerberos tickets AND the logon session key. On next login, it re-authenticates fully with the domain controller. The reason step 3 works is that the local session manager (LSASS) rebuilds the credential cache from scratch using your current password.

This fix resolves maybe 70% of cases. It's the single most effective step after the purge.

Advanced Fix (15+ minutes): Rebuild Domain Trust Relationship

You're here because neither purge nor sign-out helped. The problem is deeper — likely the machine account password (the computer's own credential) no longer matches what the domain controller has. This happens after a workstation sits off the network for weeks, or after a DC restore from backup.

Open PowerShell as Administrator.
Check the current trust status:
```
Test-ComputerSecureChannel -Verbose
```
If that returns False, repair it:
```
Reset-ComputerMachinePassword -Server "yourdomaincontroller.domain.com"
```
Replace the server FQDN with one of your actual domain controllers.
Verify the fix:
```
Test-ComputerSecureChannel -Verbose
```
Should return True now.
Reboot the machine.
After reboot, run klist purge again, then try your network resource.

Why this works: The machine account password is a shared secret between the workstation and the domain. If it drifts, Kerberos can't issue valid tickets for local user sessions. Reset-ComputerMachinePassword syncs that secret with the DC directly. What's actually happening here is the Secure Channel (NetLogon) is broken — this command re-establishes it without removing the machine from the domain.

If Test-ComputerSecureChannel still returns False after this, you might need to unjoin and rejoin the domain entirely. That's a last resort — it breaks local profile paths and app permissions.

When to Skip All This

If you're on a workgroup machine (not domain-joined), this error should never appear. If it does, you've got a different problem — likely a third-party VPN or security software interfering with Kerberos. Check your firewall logs for dropped port 88 traffic (Kerberos UDP).

Also: if you're using Windows 10 1809 or older, Microsoft patched a related bug in KB4520062 (November 2019) that caused similar session key errors after fast user switching. Update to a supported build first.