The Vps is too old to get a newer OS from the provider.

1. create /etc/apt/sources.list.d/jessie-backports.list, and fill in the following lines

deb http://archive.debian.org/debian jessie-backports main
deb http://archive.debian.org/debian jessie-backports-sloppy main

2. apt-get update -o Acquire::Check-Valid-Until=false
3. apt-get install shadowsocks-libev

the -o Acquire::Check-Valid-Until=false is the key information. Hope it is helpful.

In case you get the error “wrong architecture i386” you have to execute the following command lines as an administrator:

dpkg –add-architecture i386

apt-get update

apt-get upgrade

dpkg -i teamviewer_12.0.xxxxx_i386.deb

In case dpkg indicates missing dependencies, complete the installation by executing the following command:

apt-get install -f