Wifi interface completely gone after catalina update on 2015 MBP

macOS-Catalina-Wifi-Fix.md

https://discussions.apple.com/thread/250720965?answerId=251575762022#251575762022

1. Download the modified files (thanks Alex!) and unzip > you get a folder named WiFi_kexts
2. Boot into Recovery Mode: restart your computer while pressing and holding cmd-R
3. Open > Utilities > Terminal via Menu Bar (detailed instructions here)
4. Type csrutil disable and hit return
5. Type reboot and hit return > computer reboots normally
6. Open > Utilities > Terminal and enter cd and hit the space bar (don't hit return)
7. Drag the folder WiFi_kexts onto the Terminal window and hit return
8. In Terminal, enter sudo mount -uw / and hit return, then enter your user password and hit return
9. Enter sudo cp -r IO80211Family.kext /System/Library/Extensions/ and hit return
10. Enter sudo cp -r IO80211FamilyV2.kext /System/Library/Extensions/ and hit return
11. Right-click on Kext Utility in the folder WiFi_kexts and choose open, click open in the following dialog, authenticate with your password
12. Wait for Kext Utility to complete – this took maybe two minutes on my setup, and I got an error message in the end, as well as "All done"
13. Reboot your computer and enjoy WiFi in Catalina
14. If you want to turn on SIP again you can boot into recovery mode again and enter csrutil enable (hit return) reboot (hit return)

Files:

http://ge.tt/9yH5fLz2