Solution on macOS High Sierra when iShowU Audio Capture or other Kext cannot be installed - Kext rejected due to system policy

By: ( +David Herron; Date: October 13, 2018

Tags: macOS High Sierra » Kext » macOS Kext » iShowU Audio Capture

I needed to use OBS Studio to capture some video/audio from my desktop. On Mac OS X that in turn requires installing iShowU Audio Capture. That installation should be trivially easy, but it took me 2 weeks to work out how to get it installed, and a long email thread with the Shiny White Box support staff. The problem was the installation required that I give permission, but giving permission meant opening up the System Preferences to the Security pane and clicking on a button, and clicking on that button did not work. There is a fairly long list of possible suggestions that I have to share.

A "Kext" is a "Kernel Extension", meaning a piece of software that extends the functionality of the macOS Kernel. By the way, I'm still uncomfortable typing "macOS" after typing "Mac OS X" for the last 20 years. Apple... Why???

In the normal case, when a Kext installation requires permission a dialog is supposed to appear in front of the user. Clicking on the dialog is supposed to bring the user to the Security pane in the System Preferences. In the Security pane will be a message that an application by Such-And-So developer requires permission, and there is an Allow button. Clicking on the Allow button is supposed to bring up a dialog containing checkboxes, you tick off the checkboxes, click the OK button, and the system allows that Kext to function.

Here's a picture in case that paragraph of text did not make sense.

That's a nice and simple user experience. When it works. In my case, and the case of many others, clicking on the dang Allow button did nothing. The button would turn blue, but nothing would happen beyond this.

As always the recommendation to learn more is to enter relavent messages into your favorite search engine, like DuckDuckGo. Entering "Some system software was blocked from loading" into DuckDuckGo had some information but no quick fix.

Turns out that lots of people are having this issue and for many other applications.

The earliest suggestion was - make sure I'm doing this with a regular mouse or trackpad, not with a Wacom tablet, nor any other assistive device. In my case it is a MacBook Pro and I'm using the trackpad.

In the case of iShowU Audio Capture, there is a rigamarole required to carefully navigate the process. They supply an "Uninstall" application which lands in the Applications directory. So...

  1. Run the Uninstall application
  2. Reboot the system
  3. Run the iShowU installer
  4. Reboot the system

It's possible a system reboot will reset something and the Kext will load. This did not magically do the trick, but it's worth a try.

Debugging Kernel Extension installation quickly gets you into the geeky underbelly of the operating system. I was unable to find a nice GUI application to browse the Kext's and configure which does what and when.

For example there might be messages in /var/log/system.log.

In my case a key command was:

$ sudo kextload /Library/Extensions/iShowU\ Audio\ Capture.kext 
/Library/Extensions/iShowU Audio Capture.kext failed to load - (libkern/kext) system policy prevents loading; check the system/kernel logs for errors or try kextutil(8).
$ sudo kextutil -i -v -t /Library/Extensions/iShowU\ Audio\ Capture.kext
Defaulting to kernel file '/System/Library/Kernels/kernel'
Kext rejected due to system policy: <OSKext 0x7fc9cb76dee0 [0x7fffa44caaf0]> { URL = "file:///Library/StagedExtensions/Library/Extensions/iShowU%20Audio%20Capture.kext/", ID = "com.shinywhitebox.iShowU-Audio-Capture" }
Kext rejected due to system policy: <OSKext 0x7fc9cb76dee0 [0x7fffa44caaf0]> { URL = "file:///Library/StagedExtensions/Library/Extensions/iShowU%20Audio%20Capture.kext/", ID = "com.shinywhitebox.iShowU-Audio-Capture" }
Diagnostics for /Library/Extensions/iShowU Audio Capture.kext:

The pathname for the Kext will vary based on which Kext you are installing. The pathname shown here is for the iShowU Audio Capture application.

The key message is: Kext rejected due to system policy

The permission grant is supposed to be handled via the Security pane but as we already determined that Security pane isn't working.

Permissions grants are stored in an SQLITE3 database which you can investigate this way:

# sqlite3 /private/var/db/SystemPolicyConfiguration/KextPolicy 
SQLite version 3.19.3 2017-06-27 16:48:08
Enter ".help" for usage hints.
sqlite> select * from kext_policy;
||0|Legacy Developer: Epson|4
|com.lexmark.print.usbmerge|0|Legacy Developer: Lexmark|4
7L83S9698G|com.TrustedData.driver.VendorSpecificType00|0|Drobo, Inc.|4
7L83S9698G|com.drobo.SCSI.ThunderBolt|0|Drobo, Inc.|4
XE2XNRRXZ5||1|Canon Inc.|0
XE2XNRRXZ5||1|Canon Inc.|0
52444FG85C|com.silabs.driver.CP210xVCPDriver|0|Silicon Laboratories Inc|4
VB5E2TV963|org.virtualbox.kext.VBoxDrv|0|Oracle America, Inc.|4
VB5E2TV963|org.virtualbox.kext.VBoxUSB|0|Oracle America, Inc.|4
VB5E2TV963|org.virtualbox.kext.VBoxNetFlt|0|Oracle America, Inc.|4
VB5E2TV963|org.virtualbox.kext.VBoxNetAdp|0|Oracle America, Inc.|4
PMJ275ZTUX|com.shinywhitebox.iShowU-Audio-Capture|0|Shiny White Box Limited|4

This database is in a write-protected area of the macOS files. This database contains the flags as to which Kext's are allowed or not. Since the database is write-protected we must do something special to modify the database.

It's possible this sequence of steps is unnecessary for solving the problem. However for the purpose of definitively resetting the policies, it is necessary to boot into Recovery mode, start a Terminal window, and then modify the database. We restart in Recovery mode because doing so makes the database writable.

  1. Make sure the iShowU application is uninstalled
  2. Reboot -- hold down COMMAND-R until it starts booting
  3. When it enters the macOS Install/Recovery window, click on the Utilities menu, then click on the Terminal choice
  4. A terminal session with root privileges starts up ... so be careful

That login session is booted off a different file system than your normal macOS installation. Instead the normal macOS disk will be available as something like /Volumes/Macintosh SSD.

In the terminal window type:

# /Volumes/Macintosh\ SSD/usr/bin/sqlite3 /private/var/db/SystemPolicyConfiguration/KextPolicy 
SQLite version 3.19.3 2017-06-27 16:48:08
Enter ".help" for usage hints.
sqlite> delete from kext_policy;

This deletes all kext_policy entries, meaning all Kext's will have to be re-approved the next time you reboot.

By forcing all Kext's to be approved again, you have an opportunity to experiment with why clicking on the Allow button does not work.

I found this long discussion about the issue that contains many possible solutions: (

The bottom line is that there are many kinds of applications which can interfere with mouse input. Clicking on the Allow button fails because something interfered with the mouse click.

For example

  • Screen Sharing
  • Magic Perfs
  • Steer Mouse
  • xGestures
  • Slack .. Discord .. IntelliJ
  • ..etc..

In other words there's a whole lotta things we might install that is about improving our experience of Mac OS X, and which could be mucking with mouse clicks.

In my case the definitive change happened after exiting Google Chrome. With Chrome running clicking on the Allow button did not work, and as soon as I made Chrome quit clicking on the Allow button started to work.

At that point, with Chrome shut down, I was able to use the Allow button as designed to approve all the Kext's, and then the iShowU device showed up in the Sound preferences as designed.

The discussion does talk about ways to use keyboard navigation to get keyboard focus on the Allow button - at which point it's possible to hit the Spacebar to trigger the button. I did not explore this but it is worth a try.


This has a nice background :- (

Namely, the Gatekeeper added in Mac OS X 10.7 had some changes in macOS High Sierra (10.13) that tightened down the process of installing Kext's. It also unfortunately contributed to the problems outlined on this page.

Official documentation from Apple: (

Long list of possible culprits preventing the Allow button to work: (

« Apple's big upgrade to the Mac Mini still isn't what it should be USA advanced weapons systems vulnerable to attack over Internet, weak cybersecurity »
2016 Election 2018 Elections Acer C720 Ad block Affiliate marketing Air Filters Air Quality Air Quality Monitoring AkashaCMS Amazon Amazon Kindle Amazon Web Services America Amiga and Jon Pertwee Android Anti-Fascism AntiVirus Software Apple Apple Flexgate Apple Hardware History Apple Hardware Mistakes Apple iPhone Apple iPhone Hardware April 1st Arduino ARM Compilation Artificial Intelligence Astronomy Astrophotography Asynchronous Programming Authoritarianism Automated Social Posting AWS DynamoDB AWS Lambda Ayo.JS Bells Law Big Brother Big Data Big Finish Big Science Bitcoin Mining Black Holes Blade Runner Blockchain Blogger Blogging Books Botnets Cassette Tapes Cellphones China China Manufacturing Christopher Eccleston Chrome Chrome Apps Chromebook Chromebox ChromeOS CIA CitiCards Citizen Journalism Civil Liberties Climate Change Clinton Cluster Computing Command Line Tools Comment Systems Computer Accessories Computer Hardware Computer Repair Computers Conservatives Cross Compilation Crouton Cryptocurrency Curiosity Rover Currencies Cyber Security Cybermen Cybersecurity Daleks Darth Vader Data backup Data Formats Data Storage Database Database Backup Databases David Tenant DDoS Botnet Department of Defense Department of Justice Detect Adblocker Developers Editors Digital audio Digital Nomad Digital Photography Direct Attach Storage Diskless Booting Disqus DIY DIY Repair DNP3 Do it yourself Docker Docker MAMP Docker Swarm Doctor Who Doctor Who Paradox Doctor Who Review Drobo Drupal Drupal Themes DuckDuckGo DVD E-Books E-Readers Early Computers eGPU Election Hacks Electric Bicycles Electric Vehicles Electron Eliminating Jobs for Human Emdebian Encabulators Energy Efficiency Enterprise Node EPUB ESP8266 Ethical Curation Eurovision Event Driven Asynchronous Express Face Recognition Facebook Fake Advertising Fake News Fedora VirtualBox Fifth Doctor File transfer without iTunes FireFly Flash Flickr Fraud Freedom of Speech Front-end Development G Suite Gallifrey Gig Economy git Github GitKraken Gitlab GMAIL Google Google Adsense Google Chrome Google Gnome Google+ Government Spying Great Britain Green Transportation Hate Speech Heat Loss Hibernate High Technology Hoax Science Home Automation HTTP Security HTTPS Human ID I2C Protocol Image Analysis Image Conversion Image Processing ImageMagick In-memory Computing Incognito Mode InfluxDB Infrared Thermometers Insulation Internet Internet Advertising Internet Law Internet of Things Internet Policy Internet Privacy iOS iOS Devices iPad iPhone iPhone hacking Iron Man iShowU Audio Capture iTunes Janet Fielding Java JavaFX JavaScript JavaScript Injection JDBC John Simms Journalism Joyent jQuery Kaspersky Labs Kext Kindle Kindle Marketplace Large Hadron Collider Lets Encrypt LibreOffice Linux Linux Hints Linux Single Board Computers Logging Mac Mini Mac OS Mac OS X Mac Pro MacBook Pro Machine Learning Machine Readable ID Macintosh macOS macOS High Sierra macOS Kext MacOS X setup Make Money Online Make Money with Gigs March For Our Lives MariaDB Mars Mass Violence Matt Lucas MEADS Anti-Missile Mercurial MERN Stack Michele Gomez Micro Apartments Microsoft Military AI Military Hardware Minification Minimized CSS Minimized HTML Minimized JavaScript Missy Mobile Applications Mobile Computers MODBUS Mondas Monetary System MongoDB Mongoose Monty Python MQTT Music Player Music Streaming MySQL NanoPi Nardole NASA Net Neutrality Network Attached Storage Node Web Development Node.js Node.js Database Node.js Performance Node.js Testing Node.JS Web Development Node.x North Korea npm NSA NVIDIA NY Times Online advertising Online Community Online Fraud Online Journalism Online News Online Photography Online Video Open Media Vault Open Source Open Source and Patents Open Source Governance Open Source Licenses Open Source Software OpenAPI OpenJDK OpenVPN Palmtop PDA Patrick Troughton PayPal Paywalls Personal Flight Peter Capaldi Peter Davison Phishing Photography PHP Plex Plex Media Server Political Protest Politics Postal Service Power Control President Trump Privacy Private E-mail server Production use Public Violence Raspberry Pi Raspberry Pi 3 Raspberry Pi Zero ReactJS Recaptcha Recycling Refurbished Computers Remote Desktop Removable Storage Renewable Energy Republicans Retro Computing Retro-Technology Reviews RFID Rich Internet Applications Right to Repair River Song Robotics Robots Rocket Ships RSS News Readers rsync Russia Russia Troll Factory Russian Hacking Rust SCADA Scheme Science Fiction SD Cards Search Engine Ranking Search Engines Season 1 Season 10 Season 11 Security Security Cameras Server-side JavaScript Serverless Framework Servers Shell Scripts Silence Simsimi Skype SmugMug Social Media Social Media Networks Social Media Warfare Social Network Management Social Networks Software Development Software Patents Space Flight Space Ship Reuse Space Ships SpaceX Spear Phishing Spring Spring Boot Spy Satellites SQLite3 SSD Drives SSD upgrade SSH SSH Key SSL Stand For Truth Strange Parts Swagger Synchronizing Files Tegan Jovanka Telescopes Terrorism The Cybermen The Daleks The Master Time-Series Database Tom Baker Torchwood Total Information Awareness Trump Trump Administration Trump Campaign Twitter Ubuntu Udemy UDOO US Department of Defense Video editing Virtual Private Networks VirtualBox VLC VNC VOIP Vue.js Walmart Weapons Systems Web Applications Web Developer Resources Web Development Web Development Tools Web Marketing Webpack Website Advertising Website Business Models Weeping Angels WhatsApp William Hartnell Window Insulation Windows Windows Alternatives Wordpress World Wide Web Yahoo YouTube YouTube Adpocalypse YouTube Monetization