mtx: 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/sbin/mtx - from package: mtx

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

On Debian possible default full paths are:

/usr/sbin/mtx - from package: mtx

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

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