mk_modmap: 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/mk_modmap - from package: kbd

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

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