Account Logon Event Type 673
0x20 – KRB_AP_ERR_TKT_EXPIRED: Ticket expired
Associated internal Windows error codes
Corresponding debug output messages
? DebugLog(?Trying to renew a ticket past its renew timen?)
? DebugLog(?Trying to renew an expired ticketn?)
Possible Cause and Resolution
? The smaller the value for the Maximum lifetime for user ticket Kerberos policy setting, the more likely it is that this error will occur. Because ticket renewal is automatic, you should not have to do anything if you get this message.
To change the Maximum lifetime for user ticket setting:
1. Click Start, click All Programs, click Administrative Tools, and then click Domain Security Policy.
2. Click Accounts Policies, and then click Kerberos Policy.
3. Increase the value for Maximum lifetime for user ticket.
4. Run gpupdate /force on any client computer on which you want this policy change to take effect immediately.
I hope it will help you.