Fgo: command not found

Have You tried accessing the binary with the full path?

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/Fgo - from package: ferret-vis

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