ykpersonalize: 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/ykpersonalize - from package: ykpers

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

On Debian possible default full paths are:

/usr/bin/ykpersonalize - from package: yubikey-personalization

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

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