Too old a distro.
If you can, the best option is to replace it with latest Ubuntu 20.04 LTS
The link below is tested for latest versions (amd64):
Ubuntu 20.04, Debian 10.8 and Kali Linux 2021.1
Install Piaware 5.0 On x86_64 Machines and RPi armv7l & aarch64
The method of above link may or may not work with Ubuntu 16.04 i386.