checkgroups: 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/sbin/checkgroups - from package: leafnode

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

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