wmlflip: 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/wmlflip - from package: wesnoth-tools

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

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