create_sandbox.sh: 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/share/pear/data/symfony/bin/create_sandbox.sh - from package: php-symfony-symfony

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

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