Free contrib and repo

nano /etc/apt/sources.list

and paste this into it

deb http://http.kali.org/kali kali main non-free contrib

deb http://security.kali.org/kali-security kali/updates main contrib non-free

deb-src http://http.kali.org/kali kali main non-free contrib

deb-src http://security.kali.org/kali-security kali/updates main contrib non-free

save it

then now update

apt-get update && apt-get install -y linux-headers-$(uname -r)

after smooth completion

use

sudo reboot now

to ensure all packages and new services restart their functions