mkc_long_lines: 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/bin/mkc_long_lines - from package: mk-configure

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

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