The Vps is too old to get a newer OS from the provider.
- 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
- apt-get update -o Acquire::Check-Valid-Until=false
- apt-get install shadowsocks-libev
the -o Acquire::Check-Valid-Until=false is the key information. Hope it is helpful.
