scr-bx: 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/scr-bx - from package: BitchX

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

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