Lost network after updating to macOS 14.1.2, System Extension issues

Today, I applied the latest security patch to my Mac Studio, and on reboot, I had no networking. It appears to have been a system extension issue.

At one point, I needed to "Allow" Apple system software in System Settings. I found that strange.

I thought I'd document the issue and my resolution in case someone else runs into this.

(1) I did the usual - reboot, shutdown & restart, reboot my Eero mesh; changed from Wi-Fi to wired Ethernet. Nothing worked.

(2) I do have my own application that uses a network system extension, so I went through the system extension uninstall process (using the API). Still no joy.

I then tried to reinstall the network extensions, but that didn't seem to work. I was never prompted to open the System Settings app. I think the network system extension had not actually been removed.

I deleted the app (which should remove the network system extension). Still no joy.

Interestingly, launchctl still showed a crashed network system extension (no PID, status -9)

(3) I then disabled SIP, rebooted, and used systemextensionsctl to remove the network system extension.

While doing this, I discovered an old network system extension from several years ago tied to one of my old organizations and may have been built for Intel CPU. I deleted that too.

(If I had to guess, it might have been that old network system extension that caused the problem.)

Reenabled SIP

Rebooted.

(4) At some point I got an interesting alert from Apple about System Extension errors.

And when I opened System Settings, I had to allow an extension from Apple?!

(5) Networking is now working.

I reinstalled my application from TestFlight, installed the network system extension, and everything is still working.

(6) Summary

I lost networking after applying the security update.

Worried that it might be my program, I tried uninstalling the network system extension, but I could not cleanly uninstall and reinstall my network system extension as I've done many times before.

I found an old network system extension; deleted both network system extensions with SIP disabled.

I had to Allow Apple software.

Everything works (including my app with its network system extension installed).

I am not sure what the root cause was. My old network system extension? The fact I needed to Allow Apple software? My current app and its network system extension?

I think there may have been an issue with a software update installer (and not the OS update itself) and network system extensions. I was able to replicate the problem with Ventura 13.6.1 with Safari 16.6, and then apply the update to Safari 17.1.2 - I got the loss of all networking. But starting Sunday morning, the problem seemed to go away.

I could not replicate the issue with Sonoma because I could not rollback to an older version of Sonoma that needed to be updated.

(Is there a way to download an older version of Sonoma or Ventura than the latest version you can download from the Mac App Store?)

I documented the Ventura experiments here: https://developer.apple.com/forums/thread/742505

Lost network after updating to macOS 14.1.2, System Extension issues
 
 
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