replacekey: 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/replacekey - from package: qfits-tools

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

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