pdfcube: 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/pdfcube - from package: pdfcube

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

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