yhsm-validate-otp: 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/yhsm-validate-otp - from package: yhsm-validation-server

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

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