melt: 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 CentOS possible default full paths are:

/usr/bin/melt - from package: freeze

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/melt - from package: melt

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

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