| Previous | Next |
| DEREF_UNKNOWN_LOGON_SESSION | CANCEL_STATE_IN_COMPLETED_IRP |
REF_UNKNOWN_LOGON_SESSION
Unknown logon-session reference for REF_UNKNOWN_LOGON_SESSION
REF_UNKNOWN_LOGON_SESSION is bug check code 0x00000047. This is the reference-side partner of DEthis result. It indicates that the kernel attempted to acquire a reference on a logon-session object that was not valid in the current security bookkeeping.
How to read it in a dump
- Check whether the crash occurred during logon, logout, token creation, impersonation, or audit processing.
- The relevant evidence is the token/logon-session object, not the user name alone.
- A stale pointer or object lifetime bug can present as an unknown session.
What to check
- Review security and authentication filters, EDR/AV products, and token-manipulation code.
- Compare reference and dereference crashes if both occur.
- Look for pool corruption around security objects.
References
Dump evidence
Preserve the complete dump, the four bug-check parameters, the exact Windows build, loaded-module list, and the event timeline immediately before the stop. AllStat summarizes the condition as “this result”; that sentence identifies the failure class, while the parameters and stack determine which object, driver, processor, or subsystem instance was involved.
Analysis order
- Run WinDbg
!analyze -v, then inspect the documented meaning of each parameter instead of relying only on the probably-caused-by line. - find the earliest abnormal event: driver update, firmware change, device reset, storage error, verifier report, resource exhaustion, or application hang connected with ref / unknown / logon / session.
- keep third-party filter, security, storage, graphics, and virtualization drivers in the module inventory; removing evidence before dump analysis can obscure the responsible path.
Do not repeatedly reboot a machine affected by this result before collecting the dump and event logs. Recovery actions should follow the component identified by the stack and parameters, not merely the symbolic stop-code name.
Looking for a different code? Search another status or error code.