How to Fix Blue Screen Error 0x0000003B (SYSTEM_SERVICE_EXCEPTION) in Windows

Experiencing random BSODs (Blue Screens of Death) while gaming, especially with Rainbow Six Siege or other performance-heavy apps? Seeing error code 0x0000003B along with Credential Guard / LSA Package warnings in your Event Viewer?

What Is SYSTEM_SERVICE_EXCEPTION (0x0000003B)?

This bug check indicates a system-level process or driver made an invalid memory access. It’s often caused by:

• Faulty or unsigned kernel-mode drivers
• Incompatible antivirus/ security software
• Misconfigured or conflicting Credential Guard settings
• Malfunctioning authentication packages in Local Security Authority (LSA)

What’s Credential Guard?

Credential Guard is a Windows security feature that uses virtualization-based security (VBS) to protect login credentials like NTLM hashes and Kerberos tickets from being stolen by malware.

While powerful, Credential Guard can cause conflicts with unsigned or outdated authentication packages, especially from:

• Third-party antivirus
• Old VPN clients
• Game anti-cheat engines
• Legacy drivers

You may also see warnings like:

LSA package is not signed as expected. This can cause unexpected behaviour with Credential Guard.

Packages like:

• sfapm
• wdigest
• cloudap
• msv1_0

These entries hint that Credential Guard is blocking these LSA authentication packages, possibly causing system instability.

Quick Fixes for Gamers and Casual Users

These steps are simple and highly effective for resolving BSODs during gaming or regular use.

1. Uninstall Third-Party Antivirus or VPN

Many non-Microsoft antivirus tools inject LSA packages that aren’t fully signed or compatible with Credential Guard.

Action: Uninstall any third-party antivirus (like McAfee, Avast, Bitdefender) or security clients. Rely on Windows Defender, which works best with Credential Guard.

2. Perform a Clean Boot

• To ensure no background process is interfering:
• Press Win + R, type msconfig, press Enter.
• Go to the Services tab → check Hide all Microsoft services → click Disable all.
• Go to the Startup tab → open Task Manager → disable all startup items.
• Restart PC and see if the issue persists.

3. Temporarily Disable Credential Guard (for testing)

If LSA package signing errors persist, disable Credential Guard to check stability:

Option 1: Group Policy

• Press Win + R, type gpedit.msc
• Go to:

Computer Configuration > Administrative Templates > System > Device Guard

• Double-click Turn on Virtualization Based Security → Set to Disabled
• Reboot PC

Option 2: Registry (Advanced)

• Open Registry Editor (regedit)
• Navigate to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DeviceGuard

• Set:
  • EnableVirtualizationBasedSecurity = 0
  • RequirePlatformSecurityFeatures = 0
• Reboot PC

If your BSODs stop after this step, Credential Guard was blocking unsigned LSA packages that caused instability.

4. Run System File Checker and DISM

These tools fix corruption in system files:

sfc /scannow

Then:

DISM /Online /Cleanup-Image /RestoreHealth

Run both commands in Command Prompt as Administrator.

5. Reinstall or Update Drivers

Often, SYSTEM_SERVICE_EXCEPTION is caused by GPU or network drivers.

GPU:

• Use DDU (Display Driver Uninstaller) to fully remove your current drivers
• Reinstall latest NVIDIA / AMD drivers from official site

Network:

• Go to Device Manager → Network adapters
• Right-click and Update Driver
• Or uninstall and let Windows reinstall on reboot

Other Critical Drivers:

• Chipset drivers
• Motherboard security/firmware utilities
• Always prefer OEM versions (MSI, ASUS, Dell, etc.)

Advanced Fixes for Power Users

These are intended for experienced users or IT professionals with system-level knowledge.

6. Use Driver Verifier

• Open PowerShell or CMD as Administrator, run:

verifier

• Choose Create standard settings > Automatically select unsigned drivers
• Reboot and allow Windows to monitor for faulty drivers

7. Debug with WinDbg Commands

Run Display Context Record

.cxr /w [Address]   # Replace [Address] with the context record location

Display Stack Trace

Use:

• k, kb, kc, kd, kp, kv to trace faulty function calls

8. Rebuild MBR and BCD

• Boot into Windows installation media > Repair your computer > Command Prompt

bootrec /fixmbr
bootrec /fixboot
bootrec /rebuildbcd

9. Reset BIOS and Disable Secure Boot

• Reboot into BIOS (usually Del, F2, or Esc)
• Select Load Defaults or press F9
• Navigate to Secure Boot and set it to Disabled
• Save and exit

Optional (but Helpful) Fixes

BIOS/UEFI & Firmware Update

Outdated firmware can cause VBS-related issues.

• Visit your motherboard or laptop manufacturer site
• Look for latest BIOS/UEFI firmware updates

Follow instructions carefully, as BIOS updates are critical

Disable Virtualization If You Don’t Need It

If you don’t use Credential Guard, Hyper-V, or VBS features, turn off virtualization completely:

In BIOS:

• Disable Intel VT-x or AMD-V
• Save and exit BIOS

In Windows Features:

• Uncheck Hyper-V, Virtual Machine Platform, and Windows Hypervisor Platform

Final Summary

Need Help?

If you’re unsure which driver is causing the crash, or need help analyzing a .dmp file — just send it here and I’ll walk you through it!

Pro Tip for Gamers:

If you play competitive titles like Rainbow Six Siege or Valorant, anti-cheat systems may install low-level drivers. Ensure these are up-to-date or not clashing with Credential Guard.