Last week Apple released a minor patch for OS X in the form of a kernel extension update. Labeled “031-51913 Incompatible Kernel Extension Configuration Data 3.28.1,” the update turned out to be bugged, leaving many Mac users without a working ethernet port. Well, at least those with Macs that still have ethernet ports. It took a little time, but Apple has acknowledged the bug offered a solution for those affected.

First off, if haven’t already downloaded and installed the update, there’s no need to worry. Apple pulled the update, fixed the bug, and has released a new version. So if your Mac is showing that you need the kernel extension update, go ahead and grab it. On the other hand, if you installed the patch and your ethernet port doesn’t work, Apple’s Support site has you covered.
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Read full post here:
https://www.slashgear.com/os-x-update-leave-your-macs-ethernet-port-broken-heres-the-fix-28429374/