MacBook Pro 15 - Retina - 2014 MID - CATALINA OSX 1. Reboot with CMD + R 2. Open terminal In Utilities 3. csrutil disable 4. Reboot in normal mode 5. Terminal: cd /System/Library/Extensions 6. In order to turn off read-only in Catalina in / catalog run in terminal: sudo mount -uw / 7. Open this catalog in finder /System/Library/Extensions 8. Find file AppleThunderboltNHI.kext and right click Get Info than click Sharing & Permission 9. Instead of read-only change to read & write 10. In terminal: mv AppleThunderboltNHI.kext AppleThunderboltNHI.kext.BAK 11. After that Instead of read & write change to read-only 12. Reboot with cmd+R 13. csrutil enable 14. Reboot in normal mode and forget about the problem :)