paperkey: 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 CentOS possible default full paths are:

/usr/bin/paperkey - from package: paperkey

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/paperkey - from package: paperkey

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

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