cgnsreplace: 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 Debian possible default full paths are:

/usr/bin/cgnsreplace - from package: cgns-convert

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

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