FCluster: 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/FCluster - from package: ampliconnoise

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

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