fmfconv: 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/fmfconv - from package: fuse-emulator-utils

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

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