pp_popcon_cnt: 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/pp_popcon_cnt - from package: pp-popularity-contest

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

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