STATUS_FWP_NULL_DISPLAY_NAME (0xC0220023) Fix

The 30-Second Fix: Reset the WFP Store

Open Command Prompt as Administrator. Run this command:

netsh wfp set options netevents=off

Wait five seconds, then turn it back on:

netsh wfp set options netevents=on

This flushes the WFP state without nuking your firewall rules. I've seen this clear the error on about 1 in 3 machines. If it doesn't stick, move on.

The 5-Minute Fix: Find and Remove the Offending Rule

The error's specific — it's pointing at a rule with a null display name. You need to find that rule and kill it. Run this in an admin PowerShell:

$rules = Get-NetFirewallRule | Where-Object { $_.DisplayName -eq $null -or $_.DisplayName -eq "" }
$rules | Format-Table Name, DisplayName, Enabled, Direction -AutoSize

If you get results, note the Name property — that's the GUID. Then remove them:

$rules | Remove-NetFirewallRule -Confirm:$false

Check the error again. If it's gone, you're done. If not, or if PowerShell shows nothing, the rule might be in the registry.

Registry Deep-Dive (If PowerShell Came Up Empty)

Hit Win + R, type regedit. Navigate to:

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

Look for any value where the Name field is blank or the data string is missing DisplayName=. These entries look like random GUIDs. Right-click and delete them. Yes, it's safe — Windows rebuilds missing rules on the next boot.

Also check here:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BFE\Parameters\Policy

Same deal — any key with a blank display name gets the boot.

The 15+ Minute Fix: Full WFP Reset

If the above didn't work, something's seriously hosed. Could be a third-party security suite (Symantec, McAfee, or any VPN client) that dropped a corrupted rule. Uninstall that software first, then:

Step 1: Backup and Nuke the WFP State

Boot into Safe Mode (hold Shift while clicking Restart). Once in Safe Mode with Networking, open CMD as admin:

net stop BFE
net stop mpssvc
ren %windir%\system32\drivers\etc\hosts hosts.old

Yes, that renames your hosts file. It's fine — you'll restore it.

Step 2: Clear the Firewall Rules

Still in Safe Mode CMD:

netsh advfirewall reset
netsh advfirewall set allprofiles state on

This wipes all custom rules. Make a note of what you had before if you're in a domain environment — you'll need to reapply group policy or manually re-add exceptions.

Step 3: Restart Services

net start BFE
net start mpssvc

Step 4: Reboot and Test

Restart normally. Restore your hosts file if needed:

ren %windir%\system32\drivers\etc\hosts.old hosts

Check if the error's gone. If it's still there, you're looking at a deeper system file corruption. Run SFC and DISM next:

sfc /scannow
dism /online /cleanup-image /restorehealth

One last thing — if you're running any network traffic monitor or packet capture tool (Wireshark, Npcap, Proxifier), disable it temporarily. Those inject WFP callouts that can trigger this exact error when they misbehave.

That's the whole playbook. Start small, escalate as needed. The null display name error is annoying but rarely fatal — you'll likely have it fixed by the 5-minute mark.