aer-inject: 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:

/sbin/aer-inject - from package: ras-utils

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

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