GeoConvert: 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/GeoConvert - from package: GeographicLib

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

On Debian possible default full paths are:

/usr/bin/GeoConvert - from package: geographiclib-tools

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

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