Does your Mac have an ethernet port and do you use your ethernet port access the Internet? Did that stop working last week? If you answered yes, yes and yes it was Apple's fault but they have a fix.
Apple issued a kernel extension update for OS X last week, when they did some users found that they were unable to jack into the matrix using a cord. The good news Apple knows about it in fact they've already fixed it if you were affected here is what you need to do to check your incompatible kernel extension configuration version number.
- Hold the option key and click the Apple menu than open system information
- Dind the software section and select installations
- Look for Rows labeled "incompatible kernel extension configuration data" and find the most recent version installed
- If the number is 3.28.1 you need update the profile the steps for fixing the issue.
The fix has been issued on the Apple Support site and the instructions are easy enough to follow.