wmllint: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

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/wmllint - from package: wesnoth-tools

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