Windows Firewall with Advanced Security snap-in failed to load, Error 0x6D9

Some users have reported that after installing a security software, they are unable to access the internet and the Windows Firewall throws up an error. In such a situation, the Windows Firewall would be turned off, and the system would give an APIPA IP address. The exact error message will read:

There was an error opening the Windows Firewall with Advanced Security snap-in, The Windows Firewall with Advanced Security snap-in failed to load, Restart the Windows Firewall service on the computer that you are managing, Error 0x6D9.

Windows Firewall with Advanced Security snap-in failed to load, Error 0x6D9

Windows Firewall with Advanced Security snap-in failed to load

If you receive such an error message, obviously the first step should be to uninstall the security software. However, that alone doesn’t reverse the damage so you may have to proceed with the following solutions:

1] Perform a System Restore

After uninstalling the security software, perform a System Restore and see if that resolves your problem.

2] Check the status of these Windows Services

If the system restore doesn’t help, check the status of these three Windows Services:

  1. Windows Firewall
  2. Base Filtering Engine (BFE)
  3. Windows Firewall Authorization Driver (MPSDRV)

Press Win+R to open the Run window and type the command services.msc and hit Enter to open the Services Manager. Check if these three services are Started.

Read: Windows Firewall service does not start.

3] Reset Windows Firewall

Resetting the Windows Firewall to default might help resolve the issue. You can do it via the Control Panel, by using the built-in netsh utility or using our freeware FixWin.

Alternatively, you may execute the following commands in an elevated CMD one after the other. They will start the Services and re-register the firewall DLL file.

netsh advfirewall reset
net start mpsdrv
net start mpssvc
net start bfe
regsvr32 firewallapi.dll

Reset firewall through command prompt

If everything works fine, it should probably fix the issue.

5] Run Windows Firewall Troubleshooter

You may run the Windows Firewall Troubleshooter and see if that works for you.

6]  Reset the permissions for Microsoft Protection Service

Please backup the registry before you proceed.

The error mentioned in the previous step will occur if MpsSvc or Microsoft Protection Service lacks permissions at the registry level. The keys and permissions needed are as follows:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Epoch

Permission needed: Query Value; Set Value

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Defaults\FirewallPolicy

Permission needed: Full Control; Read

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy

Permission needed: Full Control; Read

To add the permissions do the following:

  1. Open the Registry Editor and browse to the mentioned registry keys and find “Enter the object names to select field.”
  2. Type “NT SERVICE\mpssvc” in the column. Next click “Check name” and then press OK.
  3. Add appropriate permissions as mentioned to the account.

All the best!

Posted by on , in Category Windows with Tags
Anand Khanse is the Admin of TheWindowsClub.com, a 10-year Microsoft MVP Awardee in Windows (2006-16) & a Windows Insider MVP. Please read the entire post & the comments first, create a System Restore Point before making any changes to your system & be careful about any 3rd-party offers while installing freeware.