ffDiaporama: 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/ffDiaporama - from package: ffdiaporama

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

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