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 :)