ConvertMapData: 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/ConvertMapData - from package: ncl

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

On Debian possible default full paths are:

/usr/bin/ConvertMapData - from package: ncl-ncarg

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

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