If you can connect to WiFi, then luckily updating the file to restore the functionality of the Ethernet cable is easy. If the number is 3.28.1, you need to update the profile. Look for rows labelled ‘Incompatible Kernel Extension Configuration Data’ and find the most recent version installed. Find the Software section and select Installations. To check your Incompatible Kernel Extension Configuration version number, hold the Option key and click the Apple menu. It seems that Apple accidentally blacklisted its own networking kext, which is the cause of the issue. If the number reads 3.28.1, you’ll need to update the configuration to get the Ethernet port working properly. If your Ethernet port has stopped working on your Mac, check System Information to find the version number of the Incompatible Kernel Extension Configuration file installed. Luckily, the software problem isn’t permanent and the bug can, usually, be easily resolved.Īpple has already fixed the Ethernet software problem for users going forward.

Apple has now officially acknowledged the problem on its support pages.

Many users complained about the issue online: they had randomly found their Macs no longer connecting to the Internet and their Ethernet port simply not working. If Apple hasn’t yet made the Ethernet network port on your Mac obsolete by not including it, as is the case with most Macs sold today, then it may have accidentally broke the port last week in an OS X kernel extension update.

Internet cable for macbook air