My Ethernet connection is not working on my computer (mid 2015).

I already rebooted, deleting the files "NetworkInterfaces.plist" and "preferences.plist" into the folder "/Library/Preferences/SystemConfiguration". I opened a terminal window, giving this command

sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder; say DNS cache flushed

and then I rebooted again.

But nothing seems to work.

Any idea?

Here I give the system information screen, it is Italian, sorry for this. However it says no ethernet driver is installed (could the issue be with this?) and the Thunderbolt tab says "no device connected" also when the ethernet adapter is there. I also tried to connect a VGA adaptor in order to connect a monitor and this works, so it is not the thunderbolt port.

System information gives this (sorry, it's Italian). It says that no driver is installed and in Thunderbolt section, it says no device is connected, which is of course not true.

  • P.s.: I also reset the VRAM multiple times. As expected it did not work
    – Oscar
    Feb 29, 2016 at 10:23
  • 1
    Have you tried checking the Console? I think apple.stackexchange.com/questions/229103/… might be of help here. Feb 29, 2016 at 10:30
  • Hello, sorry, how do I check the console? Command : is this the command? system_profiler | grep Network
    – Oscar
    Feb 29, 2016 at 10:51
  • UPDATE: I solved the issue, thanks to the question apple.stackexchange.com/questions/229103/… as advised by @perhapsmaybeharry Thanks. It was some further network configuration file in "/Library/Preferences/SystemConfiguration", in "/Library/Preferences" and in "~/Library/Preferences"
    – Oscar
    Feb 29, 2016 at 11:18
  • @Oscar, you may want to post your last comment as an answer and then mark it as solved. Feb 29, 2016 at 15:09

1 Answer 1


If this is recent, you may be the victim of a bad malware protection update from Apple. They have posted a support article explaining how to check if this was the cause, and how to fix it.

First, check your version number

  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.

If you can connect to Wi-Fi, follow these steps to update to version 3.28.2

  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.

If you can't connect to Wi-Fi, follow these steps to update to version 3.28.2

  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.
  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 support.apple.com/kb/HT205956.
    • 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.

Alternatively, if you confirmed that your Mac has Incompatible Kernel Extension Configuration Data version 3.28.1, you can also restart your Mac into OS X Recovery mode, then select Reinstall OS X. You can reinstall OS X on your drive without reformatting it.

  • Please put the information from the link in the answer just in case it is ever deleted.
    – iProgram
    Feb 29, 2016 at 15:08
  • 1
    Will do when back at a laptop... it's too long and requires too much reformatting to do from here.
    – calum_b
    Feb 29, 2016 at 15:09

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