ErrorFindly
0x00000047BSODCritical

0x00000047 — Ref Unknown Logon Session | Blue Screen Fix Guide

REF_UNKNOWN_LOGON_SESSION

Windows XPWindows VistaWindows 7Windows 8Windows 10Windows 11

What Does 0x00000047 Mean?

An attempt was made to reference an unknown logon session.

Real-World Causes

  1. 1Security subsystem error
  2. 2Corrupted logon session table
  3. 3Authentication service failure

Symptoms

  • ⚠Blue screen with stop code REF_UNKNOWN_LOGON_SESSION
  • ⚠System reboots unexpectedly
  • ⚠Possible data loss from unsaved work

DIY Fix

Beginner-friendly steps you can try at home

  1. 1Restart your computer
  2. 2Run full antivirus scan
  3. 3Run System File Checker (sfc /scannow)
  4. 4Check Windows Update

Advanced Fix

For experienced users and IT professionals

  1. 1Analyze minidump for security subsystem failure
  2. 2Check security event logs
  3. 3Verify system file integrity with DISM
  4. 4Review Group Policy and security settings

Frequently Asked Questions

What causes REF_UNKNOWN_LOGON_SESSION?
An attempt was made to reference an unknown logon session.
Can I fix Ref Unknown Logon Session myself?
In many cases yes. Start with basic troubleshooting like restarting, updating drivers, and running System File Checker. If the issue persists, advanced analysis of crash dumps may be needed.

Related Error Codes

0x00000046Deref Unknown Logon Session0x00000029Security System

About the Author

Windows Troubleshooting Team

Verified against official Microsoft documentation and real-world diagnostic data. Error behavior confirmed across Windows 10, Windows 11, and Windows Server.