compton-trans: 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/compton-trans - from package: compton

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

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