Windows Firewall Error 0x6d9 “The snap-in failed to load”

When you open the Windows Firewall (with Advanced Security) applet, the following error may show up:

There was an error opening the Windows Defender Firewall with Advanced Security snap-in

The Windows Defender Firewall with Advanced Security snap-in failed to load. Restart the Windows Defender Firewall service on the computer that you are managing. Error code: 0x6D9.

The Win32 error code 0x6D9 (“0x800706D9” or EPT_S_NOT_REGISTERED) means “There are no more endpoints available from the endpoint mapper.”

Attempting to start the Windows Firewall service (“mpssvc“) may show that the service gets stuck in the “Start Pending” state.

Cause

The Windows Firewall error 0x6D9 may occur if one or both of the following service registry keys are corrupted, or their permissions are incorrect.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MpsSvc

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Bfe

Resolution

To resolve the issue, follow these steps to replace the SharedAccess, BFE, and MpsSvc registry keys from another computer running the same Operating System. The following steps should restore the missing keys/values and fix incorrect registry permissions.

1. In the C:\ drive, create a folder named “Registry” — C:\Registry.
2. Download firewall_fix_windows_10.zip or firewall_fix_windows_11.zip
3. Extract the four files from the Zip file to C:\Registry.
4. From the C:\Registry folder, right-click “Run.bat” and choose “Run as administrator.”
   
   (Note: You should see the output “The operation completed successfully” for each command.)
   
5. Restart Windows.

The Base Filtering Service, Internet Connection Sharing (ICS), and Windows Firewall services should now be fixed.