fcconv: 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/fcconv - from package: esys-particle

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

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