Het forum

A installation-guide for Ubuntu 18.04 Bionic Beaver is missing on 

https://www.playonlinux.com/de/download.html

wget -q "http://deb.playonlinux.com/public.gpg" -O- | sudo apt-key add -
sudo wget http://deb.playonlinux.com/playonlinux_bionic.list -O /etc/apt/sources.list.d/playonlinux.list
sudo apt update
sudo apt install playonlinux

Worked for me... but didn't install wine-stable or xterm as a dependecy. Anyways, adding the guide would have helped me to install the latest version faster.

Thanks, we will see what's is going on with the dependecy.