checkbot: 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/checkbot - from package: checkbot

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

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