How to Check For and Fix Apple's Recent Update that Disabled Ethernet

This post serves more as a Public Service Announcement (PSA) than a tech tip, but it’s something that you should be aware of, especially for those who use the Ethernet port on your MacBook Pro or iMac. Apple recently released a minor update to OS X which adversely affected the functionality of the Ethernet port, to the extent of disabling the port altogether.

I personally wasn’t affected right away because I don’t use my Ethernet port very often, but it’s something that we should all be aware of to avoid the disruption. In this post, I will walk you through how to check to see if you are affected (not all users are affected) and how to fix it if you are.

How to check if you are affected

To see if you are affected by this buggy kernel update, do the following:

1) While pressing the Option key, choose System Information from the Apple menu.

2) Expand the Software section and select Installations.

3) Click the Software Name column header to sort the list alphabetically.

4) Look for “Incompatible Kernel Extension Configuration Data.” If the most recent version installed is 3.28.1, follow the steps below.

How to fix it using Wireless

If you can connect to a wireless network, do the following:

1) Open the Terminal app.

2) Enter this command to update to the current version of the “Incompatible Kernel Extension Configuration Data” kernel extension:

sudo softwareupdate --background

3) Quit Terminal and restart your Mac

How to fix it manually

If you aren’t able to connect to a wireless network or would prefer to make the change manually, do the following:

1) Restart from OS X Recovery by holding down Command-R while your Mac starts up.

2) Select Disk Utility from the list of OS X Utilities (Finder > Applications > Utilities).

3) Select your drive from the list of internal drives in the sidebar. The default name is “Macintosh HD.” Your drive might have a different name or location, if you renamed or moved it.

4) If the drive name is dimmed, your drive might be protected by FileVault. Choose File > Unlock from the Disk Utility menu, then enter your FileVault password. 

5) Choose File > Mount in Disk Utility to mount your drive, if it's not already mounted. 

6) Quit Disk Utility. 

7) To make it easier to enter the command shown in step 9, you might want to copy it from Safari:

  • Choose Get Help Online from the OS X Utilities list, then go to
  • Select the command in step 9, copy it, then quit Safari before you continue to the next step. 

8) Choose Utilities > Terminal to open the Terminal app.

9) Type or paste the following command as one line in Terminal, then press Return. Replace Macintosh HD with the name of your hard drive, if different: 

rm -rf "/Volumes/Macintosh HD/System/Library/Extensions/AppleKextExcludeList.kext

Now complete these steps to update to the current version of the “Incompatible Kernel Extension Configuration Data” kernel extension:

1) Quit Terminal.

2) Choose Restart from the Apple menu. After your Mac restarts, your Ethernet connection should work. 

3) Open Terminal and enter this command:

sudo softwareupdate --background

4) Quit Terminal

5) Choose Restart from the Apple menu.

Posted on March 1, 2016 and filed under How To, Mac.