weights: 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/lib/fastdnaml/bin/weights - from package: fastdnaml

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

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