Issue trying to route Cuckoo traffic through a VPN

Hi everyone, I'm trying to configure Cuckoo sandbox to route traffic through a VPN, however, I'm getting the following error

https://preview.redd.it/yqn0zoja4qe91.png?width=1298&format=png&auto=webp&s=48d03c745fdd201bac34ce4fd1d07c7257386c7d

I have followed all the steps in the Cuckoo documentation to set up the VPN and have configured tun0 in both the VPN .conf file and in the rt\_tables. Therefore, what is going on here and how may I fix it?

cuckoo malware traffic vpn