Yup… something strange here… seems to be complaining that the repository isn’t working… problem with it’s signature? perhaps I should start over… 
I tried to copy and paste the entire error but it contains too many links and I’m only allowed two.
kali@kali:~$ sudo apt-get update && upgrade
[sudo] password for kali:
Get:2 http://http.re4son-kernel.com/re4son kali-pi InRelease [8133 B]
Err:2 http://http.re4son-kernel.com/re4son kali-pi InRelease
The following signatures were invalid: EXPKEYSIG 11764EE8AC24832F Carsten Boeving <carsten.boeving@whitedo me.com.au>