cups-genppdupdate: 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 CentOS possible default full paths are:

/usr/sbin/cups-genppdupdate - from package: gutenprint-cups

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/sbin/cups-genppdupdate - from package: printer-driver-gutenprint

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

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