cinnamon-screensaver: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/cinnamon-screensaver - from package: cinnamon-screensaver

You may install the required package with command apt-get install {package}
Error in other languages:
cinnamon-screensaver: bevel nie gevind nie
cinnamon-screensaver: comandă negăsită
cinnamon-screensaver: comando não encontrado
cinnamon-screensaver: commande introuvable
cinnamon-screensaver: command not found
cinnamon-screensaver: käsku ei ole
cinnamon-screensaver: không tìm thấy lệnh
cinnamon-screensaver: komanda nerasta
cinnamon-screensaver: Kommando nicht gefunden.
cinnamon-screensaver: kommandot finns inte
cinnamon-screensaver: komut yok
cinnamon-screensaver: nie znaleziono polecenia
cinnamon-screensaver: níor aimsíodh an t-ordú
cinnamon-screensaver: no se encontró la orden
cinnamon-screensaver: no s'ha trobat l'ordre
cinnamon-screensaver: opdracht niet gevonden
cinnamon-screensaver: parancs nem található
cinnamon-screensaver: perintah tidak ditemukan
cinnamon-screensaver: príkaz nenájdený
cinnamon-screensaver: příkaz nenalezen
cinnamon-screensaver: команда не найдена
cinnamon-screensaver: командата не е открита
cinnamon-screensaver: 命令找不到
cinnamon-screensaver: コマンドが見つかりません