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After a password change on my account, I keep getting locked out by exchange with this error on our domain controller:

Pre-authentication failed:
User Name:  william
User ID:        [domain]\william
Service Name:   krbtgt/[domain]
Pre-Authentication Type:    0x2
Failure Code:   0x18
Client Address: [exchange IP]

I've already looked into:

  • My cellphone, updated the account, and even removed the account.
  • Services/tasks on the server running as me (there are none).
  • SMTP traffic to the mail server (there is none during this).
  • Any requests to the server (using wireshark, the kerberos request just comes out of nowhere every 60 seconds).
  • Disabled pre-auth on the account.
  • Rolled back my password to the old password.
  • Disconnecting my mailbox.

Any ideas? I'm looking to schedule a reboot tonight, but this is rough, I can't get anything done.

share|improve this question
Look at your desktop (assume Windows 7) | Control Panel | Windows Card Space. Do you have anything cached ? if so remove it. – knothead Apr 30 '13 at 17:34
Nope, don't have any cards to cache. – StrangeWill Apr 30 '13 at 17:36
Other software or services on the Exchange server that would use your account? Still logged in to an old RDP session? – TheCleaner Apr 30 '13 at 18:00
Logged out of all RDP sessions, verified from 2nd account. No software or services running as my account. – StrangeWill Apr 30 '13 at 18:02
In your Exchange mailbox, any additional mobile devices? Maybe an iPad or similar? If not, that's all I can think of. – TheCleaner Apr 30 '13 at 18:14

Turned out to be AppAssure, it doesn't throw any errors when auth fails, and it doesn't log anything when it can't mount the exchange datastore, so looking through services/event logs/tasks/AppAssure console didn't show anything.

share|improve this answer
Backup Software should definitely not be running as your user account, nor any user's account. It should have it's own service account (if it can't run as the local system). – Chris S May 1 '13 at 13:52
It wasn't running as, which made it harder to hunt down, it was credentials internally it used for mounting and checking the exchange datastore, which I believe needs exchange management roles. – StrangeWill May 1 '13 at 20:58

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