ttyrec: 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/ttyrec - from package: ttyrec

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

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