xpaaccess: 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/xpaaccess - from package: xpa

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

On Debian possible default full paths are:

/usr/bin/xpaaccess - from package: xpa-tools

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

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