When McAfee firewall won’t turn on on Mac, restore it by granting permissions, updating the app, and reloading its network components.
Start Here: Quick Fixes That Solve Most Cases
You want the firewall up right now. Start with the fast wins below. These steps are safe, reversible, and take minutes. Run them top to bottom.
| Step | Where To Click | Why It Helps |
|---|---|---|
| Check macOS Firewall | System Settings > Network > Firewall | Confirms the built-in firewall is available while you fix McAfee. |
| Reboot The Mac | Apple menu > Restart | Reloads system extensions and network filters used by security apps. |
| Update McAfee | Open McAfee > About or Settings > Update | New builds repair firewall bugs and refresh drivers. |
| Unlock Then Enable | McAfee > Mac Security > Firewall > click the lock | Gives the app permission to flip firewall controls. |
| Grant Required Access | System Settings > Privacy & Security | Approves network extensions and items the firewall needs. |
| Reconnect Network | Wi-Fi off, wait 10 sec, on | Forces fresh rules to attach to the active interface. |
Why McAfee Firewall Won’t Turn On On Mac: Root Causes
Three buckets explain almost every failure. Missing permissions. Out-of-date components. Conflicts with other filters or profiles. Clear each blocker cleanly, then relaunch the firewall to confirm the fix.
Missing Or Blocked Permissions
McAfee needs network extensions, notifications, and full disk access for certain tasks. If any prompt was dismissed, the toggle can gray out or spring back to Off. Open System Settings and approve items tied to McAfee. On Apple silicon, some models also show an “Allow” banner for system extensions after install or update. Skip that and the driver never loads, which leaves the switch stuck.
Out-Of-Date Build Or Corrupted Install
Older releases hit a firewall defect in early 2024, while partial upgrades can leave stale drivers behind. The clean path is update first. If that fails, remove and reinstall the current build. A fresh install replaces the network filter bundle and clears broken launch items.
Conflicts With Other Network Filters
VPN clients, other antivirus tools, and content filters can hook the same network stack. Two tools racing for control cause rules to fail or the status to misreport. Turn off or remove the extra tool while you test. If the firewall springs back, keep a single owner for filtering or set clear exclusions on both sides.
Step-By-Step: Turn The McAfee Firewall Back On
Follow this sequence. After each step, try the firewall switch again. Stop when it stays On and shows an active status.
1) Confirm The Built-In macOS Firewall State
Apple includes a simple firewall you can use during troubleshooting. Go to System Settings > Network > Firewall and switch it On if you want a baseline layer while you fix McAfee. This does not replace McAfee rules, but it adds basic inbound blocking while you work.
2) Update McAfee To The Latest Release
Open the McAfee app. Check the update panel and apply any pending patch. If the app asks for a restart, accept it. New versions replace the network extension that drives the firewall and address known glitches. Many cases clear right after this step.
3) Grant Every Permission McAfee Requests
Open McAfee, then the firewall panel. If the padlock appears, click it and enter your Mac password. In System Settings, review Privacy & Security panels such as Full Disk Access, Network extensions, Notifications, and Login Items. Approve the McAfee entries you see. If macOS shows an “Allow” button after installation, press it to load the extension.
For a clear walkthrough from the vendor, see the short guide that explains the lock icon, the password prompt, and which switches to approve: Grant permissions for McAfee Firewall.
4) Power-Cycle Network Filters
Toggle Wi-Fi off, wait ten seconds, then turn it on. If you use Ethernet, unplug and re-seat the cable. This forces macOS to reload active filters and can wake a stuck ruleset. Test the firewall switch again right after reconnection.
5) Remove Conflicting Tools
Quit VPN apps, traffic shapers, and any other antivirus product. If the firewall switch works after that, add mutual exclusions or keep only one tool that owns filtering. Mixing two drivers on the same stack is a common cause of flapping status.
6) Reset McAfee Components Cleanly
If the toggle still flips back, reinstall the app. Use the built-in uninstaller found in Applications. Then grab the latest download from your account and install fresh. This clears broken drivers, bad caches, and blocked launch items in one pass.
7) Recheck System Extension Approval
After a reinstall, some Macs ask you to allow the driver. Look under Privacy & Security for prompts tied to system extensions. Approve them, then try the firewall again. If the prompt never appears, open the firewall panel, click the lock, and wait a few seconds to trigger it.
When The Switch Still Won’t Stick
If you reached this section, basic steps fell short. Move on to deeper checks tied to macOS settings, profiles, and user-level items that can block the service from starting at boot.
Check Login Items And Background Items
Open System Settings > General > Login Items. Ensure McAfee launch items are allowed. If they’re blocked, the firewall service won’t start on login and the toggle won’t hold. Remove old, unknown entries that claim to monitor traffic; they can collide with McAfee’s starter.
Look For Old Security Suites
Old leftovers can leave kernel or network bits behind. If you used another suite, run its official remover and restart. A quick clue is a second menu bar icon for filtering or web shields. Once those are gone, try the McAfee firewall again.
Review macOS Profiles
Profiles from work or school can enforce network rules that collide with McAfee. In System Settings > Privacy & Security > Profiles, remove any profile you don’t need. If the Mac is managed, ask your admin whether a content filter or packet filter profile is present.
Test On A Fresh User Account
Create a new admin user and sign in. Install only McAfee and test the firewall. If it works there, the issue lives in the original user’s settings, launch agents, or login items. Migrate only clean items back and retest the toggle after each move.
macOS Sonoma And Later: Small Quirks To Watch
Newer macOS releases lean on system extensions and network extensions. That model is stable, yet it makes permission prompts easy to miss during install. If the setup window was hidden behind System Settings, you might have closed it without pressing Allow. Open the firewall panel again and watch for prompts. If nothing shows, remove and reinstall the app so the prompts reappear. Also check for an Allow banner under Privacy & Security right after the first reboot.
Error Messages And What They Mean
Use the table as a decoder. Match the wording you see to a cause and a next move that clears it.
| Message | Likely Cause | What To Try |
|---|---|---|
| “Firewall can’t be enabled” | Permission not granted | Unlock the panel, approve system extension, then retry. |
| “Driver failed to load” | Old build or blocked extension | Update McAfee, then approve any Allow prompts in Privacy & Security. |
| “Another firewall is active” | Competing filter or VPN | Quit other security apps and VPNs; test again. |
| “Service not running” | Login item blocked | Allow McAfee items in Login Items & Extensions. |
| Toggle flips back to Off | Rules not applied | Reboot, reconnect network, or reinstall to refresh components. |
Clean Reinstall: The Safe Way
A careful reinstall fixes stubborn cases without leaving scraps behind. Follow this order so the firewall service starts cleanly on first boot and keeps its status through restarts.
Back Up, Sign Out, And Reboot
Save your work. Sign out of McAfee if the app shows an account panel. Reboot once so no stale pieces are in memory. This first restart shortens the time the uninstaller spends trying to stop running items.
Use The Official Uninstaller
Open Finder > Applications. Double-click the McAfee uninstaller. Enter your admin password when asked. When it finishes, restart. Avoid dragging the app to Trash; that leaves support files and launch daemons that can block a clean reinstall.
Install The Current Build
Download the latest installer from your account. Run it and wait for the prompts about extensions and permissions. Approve every dialog during setup. If a prompt hides behind another window, bring it forward and press Allow. Then open the firewall panel and click the lock to make the switch active.
Approve Prompts And Test
Right after install, open the firewall panel and click the lock. If macOS shows an Allow button tied to system software from the developer, approve it. Then turn the McAfee firewall On and watch the status stay green for at least a minute. Reboot once and confirm the state persists after login.
Extra Tips That Save Time
Keep only one network filter tool on the Mac. Leave the Mac firewall On during any McAfee fix. Turn on automatic updates inside McAfee so firewall drivers stay current after OS updates. If you run a VPN, set it to start after McAfee loads to avoid race conditions. If you use network profiles from work, ask the admin to exclude McAfee from any packet filter rules. When you game or stream, avoid switching VPN protocols mid-session; that often drops rules and causes the toggle to reset.
Trusted References For Specific Buttons
If you want the exact panels and wording, these pages match current macOS and McAfee screens. Apple shows the path to the built-in firewall switch. McAfee shows the permission prompts and the lock icon used to enable changes.