tkaeca: 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/tkaeca - from package: aegis-tk

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

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