yade: 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/yade - from package: yade

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

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