Fsort: 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/Fsort - from package: ferret-vis

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

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