System Extension Blocked - but can't allow extension

There is a workaround for this. It isn't a great workaround, security-wise, but it does get you back to the behavior of macOS 10.12. Basically, you can turn off the security feature requiring user approval of Kernel Extensions.

First, boot into Recovery Mode by rebooting and pressing and holding command-R as soon as you see the Apple logo. On my machine, I had to hold command-R for quite a while, at least 60 seconds.

Eventually you will see a screen that gives you a couple of options, including reinstalling or running Disk Utility. If you look at the top of the screen, where the Apple menu would ordinarily be, you will see a "Utilities" drop-down menu. Click on that and select Terminal. A window will open up that allows you to type text-based terminal commands.

You will see a "$" prompt in the terminal window. Type the following:

spctl kext-consent disable

then press Return. You should see:

Kernel Extension User Consent: DISABLED

Please restart for changes to take effect.

Then reboot your Mac, and you should be good. You will no longer see the notification panes telling you a Kernel Extension was blocked; they will all be automatically allowed, just as they were in macOS 10.12.

I would recommend waiting until 10.13.1 or 10.13.2 to see if the issue gets fixed, and then undoing this fix by repeating the same steps, but typing

spctl kext-consent enable

instead.

For more information, see the following website:

User Approved Kernel Extension Loading… – Pike's Universum

I had this same problem and fixed it by booting into Safe Mode, going to System Preferences -> Security and Privacy and then it allowed me to click the "Allow" button and it disappeared. I still had to reboot once more before VMWare would run my VM.

I had the same issue in regards towards other software preventing my click form registering in the Security & Privacy Panel, when the Allow request popped up. I just used the Tab key to navigate to the Allow button and then pressed spacebar to select it and it worked perfectly. Didn't need to disable anything. 🙂

@johnpalmedina

I know the original issue was posted last year but this just happened to me. I am on OSX 10.13.3 and recently updated my AVG antivirus that required a kernel extension. I clicked and clicked on the privacy and security ALLOW the AVG to load a kernel extension but nothing happened. Until I found this article and noticed that I too was using MAGICPREFS. I quit MAGICPREFS and then clicked ALLOW in the privacy and security prefs. Worked like a charm. Thanks

I had the same problem and solved it by temporary disabling a software running on my Mac : iTunes Volume Control (https://github.com/alberti42/iTunes-Volume-Control). Great soft by the way.

That software must catch key strokes, like other softwares cited here (Chrome for example).

Disabling it let me click on "Allow" button.

I was experiencing a similar issue where clicking "Allow" in Security preferences did nothing. I uninstalled and reinstalled the software, then booted up in safe mode. After doing this I was able to click "Allow" and the dialog dismissed. I then rebooted normally and the software was behaving normally.

Thank you, this is exactly what worked for me when I had the same issue with Sophos antivirus. (High Sierra 10.13.4) No need to uninstall the app first, though - just start in safe mode, open the security preferences, unlock and click Allow. It will prompt to restart.

I had the same issue but was able to resolve it after logging in as the primary admin user (You may not have one, try to create a second admin user if you don't). As my user, the popup dialog that is created after clicking allow was not coming up. My guess is that the system thinks I don't have rights to all the extensions that I was trying to install. Hope it works for everyone.

I had VLC working in the background. There was an Error Dialog opened. That seems to prevent focusing and clicking ALLOW in the SYSTEM EXTENSIONS WINDOWS LOLZ! Close VLC and you will be able to click ALLOW :-)

macOS Hight Sierra really *** *** :-)

I have experienced with some of our users the same problems clicking on the allow button even in front of the Mac. What does seem to work a lot more reliably but is not suitable for many people is using an MDM system and pushing out a profile to 'whitelist' either individual Kernel Extensions or particular manufacturers team ids. See Prepare your institution for macOS High Sierra 10.13.4 - Apple Support

I therefore whitelist all the most likely manufacturers i.e. VMware, Parallels, VirtualBox aka Oracle, Sophos, Sonnet Tech, Highpoint, ATTO, Tunnelblick and so on.

This article discusses how to find the team ids and bundle ids. See - User Approved Kernel Extension Loading… – Pike's Universum

What I regard as incredibly stupid on Apple's part is that macOS as standard includes Kernel Extensions for Sonnet Tech, ATTO and Highpoint and yet these also are not trusted even though they are built-in to macOS.

High five to this man! Spent ages trying to work out why clicking Allow wasn't working - temporarily turning off MagicPrefs fixed it.

The 'Allow' button is disabled if you're running anything that modifies your mouse, touchpad or usb behaviour. This could be USB Overdrive, Better Touch Tool, etc.

Restarting my Mac in safe mode solved this blocking problem. Finally the ALLOW button works.

Hello,

for some reason I had the same issue, what helped me was to use TAB and then space to "click" the Allow button.

Hope it helps

Have you tried doing it in Safe Mode? That was the solution for me. I use it every time I need to allow a system extension now.