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

Because of security reasons pressing the Allow button won’t take effect if you are connecting to the machine via Remote Desktop, or if the mouse/trackpad is emulated by a 3rd party application (MagicPrefs, BetterTouchTool, Synergy, etc.)

I have a third party app MagicPrefs. Which allows some additional controls to my mouse gestures, I had to disable this in order for the system to recognize the click on the allow button.

Hope this helps anyone with the the same issues.

My migration failed due to an old driver (Silicon Image 3132 PCIe eSATA card), resulting in a disturbing reboot loop until I turned off my external disk.

That installation interruption, I think, resulted in a corrupted Kernel Extension db. At least, sqlite3 didn't like the file very much. When you list the tables in that file, what's SUPPOSED to happen is this:

$ echo .tables | sqlite3 /private/var/db/SystemPolicyConfiguration/KextPolicy

kext_load_history_v3 kext_policy

I got the error: "database disk image is malformed"

I was able to fix this by booting into Recovery mode (cmd-R when the system comes up), moving the KextPolicy db out of the way in the Terminal app, and re-installing High Sierra.

Details: Once the system was up in recovery mode, I fired up the Terminal app (under "Utilities") and did this:

# cd /Volumes/System\ Drive/private/var/db/SystemPolicyConfiguration

# mv KextPolicy /Users/Shared

# mv migration.plist /Users/Shared

(Note: your system drive might be named something other than "System Drive". Also, I just wanted to make a backup of the files someplace where the installation process won't clobber them.)

I then quit the Terminal app and just re-installed High Sierra. 55 minutes later (or there abouts) I was able to list the tables in the KextPolicy db AND, best of all, VMWare fusion worked and no other Kext complaints were in evidence.

You can search the Internet for things like "SystemPolicyConfiguration" or "sqlite3 'database disk image is malformed'" to get a bunch of background info about this.

But, that said, I'll probably spend some part of my Christmas long weekend reinstalling this guy from scratch.

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. 🙂

Okay, last update from my journey. Like I expected, installing High Sierra over the second buggy one did nothing, it was just a waste of an hour. So I went nuclear again. Erased the disc, did a clean install and took my time putting my apps and data back this time. No sense spending a day just copying stuff if I have to redo it all again the day after. So I took my time, grabbed the most used things from the App Store, put vital data back and started working on the machine like normal. Put stuff back when I needed it or when I had some spare time. At this point everything is back where it belongs, all my apps are here, et and everything works fine. No issues whatsoever (just the media keys on the keyboard that are not fixed to iTunes anymore but switch over to whatever app they want :/ ).

So I'm not sure what happened with my first clean install, but the second fixed everything. That second install was done with the same bootable USB drive, not an updated one, so your guess is as good as mine as to why things went haywire again.

But at least I'm back to business as usual 🙂 It took me over a week, and I have a clean system now (which to be fair might not be such a bad thing after a decade of updates).

So for anyone else with this problem, unfortunately it seems like a clean install is your only option 😟

Hi, there is a fast solution for this "allow button problem" and is that you can disable the allow kernel extension mess.

You should boot your OsX in Recovery Mode (Restart, and press Command R)

When you are in Recovery Mode, go to the menu bar and open a Terminal and run the next command:

$spctl kext-consent disable

Then reboot the OsX normally. All the mess are gone and all the kext are loaded as usual.

Reseting the NVRAM will revert this changes!

😀

I managed to fix this issue. You'll have to disable SIP to let the Kext load without any interference.

Steps to disable SIP:

1. Boot into recovery mode (Hold CMD + R during booting process).

2. Open terminal and enter the following command: csrutil disable

3. Reboot the system. This should allow the kernel extensions to load without any interference.

(Re-enable SIP using csrutil enable)

This is clearly not the safest way to fix this, but it worked for me. I wasted many weeks because of this issue. It's truly sad that macOS has become less developer-friendly over the years.

@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.

Here is another update for you guys.

I restored the week old Time Machine Back-up, from before High Sierra was installed, that resulted in a perfectly working machine, but with outdated data. After making sure everything worked as it should, I went to the App Store and downloaded High Sierra again and installed it. First thing I tried was installing the drivers again, and three guesses what happened. System Extension was Blocked, no Allow button, back to square #1. Played around with it a bit and it was exactly the same, not only the extension problem, but Time Machine couldn't connect to my Time Capsule and DMGs started making Finder Crash again.

So I was left with the last option, a clean install 😢

Which is what I did, I made a bootable USB drive on my MacBook, since that didn't work on my iMac, it kept crashing on downloading the installer or putting it to USB. So MacBook to the rescue. I rebooted the iMac into recovery, wiped the Fusion drive and installed MacOS from the USB disk. Which resulted in a perfectly smooth and operational MacOS High Sierra installation. First thing I did was get my drivers, installed them, got the System Extension Blocked message, headed to Security and Privacy and lo and behold, there was an Allow button! I clicked it, rebooted my machine like the installer wanted and my 3D mouse worked like a charm 🙂

Messed around with DMGs a bit, seemed to work fine, so I connected the USB drive with my latest Back-up (after HS install) and started putting all my files back manually, luckily that's an easy process since you just get your file structure in the back-up, so it's just a matter of dragging and dropping files back to where they should go.

Again, it's 1TB so that took hours, but hey, I had everything back in working condition 🙂

Until last night. I was mostly done putting everything back, my files are back on there, the smaller apps were moved or redownloaded, just had a few more to go when I noticed an MacOS update on my macbook. So I headed over to the App Store on the iMac, no update. Clicked the tab again "Error, could not connect..." Euhm... Opened Safari... back screen. Restarted Safari, black screen. No sites opened. Opened Chrome, no issues, worked fine.

Mail worked, Photo's didn't sync. iTunes Store works fine, Maps works, App Store browsing works, just not updates or actually downloading apps. And Safari does absolutely nothing. Page starts to load, blue bar starts running, stops. Page stays white, no error's noting, just stay like that.

I made a new test user account, and there everything works fine, so something in my user seems messed up, but I did nothing that could have messed it up. I moved some files, installed some often used and trusted apps. How the heck did that mess up Safari from working and some Apple Apps from connecting?

So I "fixed" my original problem by nuking it. But then a new issue posed up. I'm reinstalling MacOS over it again, which will 99% not do anything, but hey, it's worth a try before I call Apple again. I'm getting really tired of this. I haven't been able to use my iMac in over a week now :/

So to everyone with the "System extension blocked" issue, it seems like a clean install is the only way to "fix" it. I hope no one else encounters other issues along the way, though.

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 *** *** :-)