CRMFPopClient: 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/CRMFPopClient - from package: pki-java-tools

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

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