firstaidkitrevert: 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/firstaidkitrevert - from package: firstaidkit-engine

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

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