cinnamon-session-cinnamon2d: command not found

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

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

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-session-cinnamon2d - from package: cinnamon

You may install the required package with command apt-get install {package}

Error in other languages:
cinnamon-session-cinnamon2d: bevel nie gevind nie
cinnamon-session-cinnamon2d: comandă negăsită
cinnamon-session-cinnamon2d: comando não encontrado
cinnamon-session-cinnamon2d: commande introuvable
cinnamon-session-cinnamon2d: command not found
cinnamon-session-cinnamon2d: käsku ei ole
cinnamon-session-cinnamon2d: không tìm thấy lệnh
cinnamon-session-cinnamon2d: komanda nerasta
cinnamon-session-cinnamon2d: Kommando nicht gefunden.
cinnamon-session-cinnamon2d: kommandot finns inte
cinnamon-session-cinnamon2d: komut yok
cinnamon-session-cinnamon2d: nie znaleziono polecenia
cinnamon-session-cinnamon2d: níor aimsíodh an t-ordú
cinnamon-session-cinnamon2d: no se encontró la orden
cinnamon-session-cinnamon2d: no s'ha trobat l'ordre
cinnamon-session-cinnamon2d: opdracht niet gevonden
cinnamon-session-cinnamon2d: parancs nem található
cinnamon-session-cinnamon2d: perintah tidak ditemukan
cinnamon-session-cinnamon2d: príkaz nenájdený
cinnamon-session-cinnamon2d: příkaz nenalezen
cinnamon-session-cinnamon2d: команда не найдена
cinnamon-session-cinnamon2d: командата не е открита
cinnamon-session-cinnamon2d: 命令找不到
cinnamon-session-cinnamon2d: コマンドが見つかりません