mech-dump: 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/mech-dump - from package: perl-WWW-Mechanize

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

On Debian possible default full paths are:

/usr/bin/mech-dump - from package: libwww-mechanize-perl

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

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