mcmfmt: 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/mcmfmt - from package: mc

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

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