update-openrocket: 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/sbin/update-openrocket - from package: openrocket

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

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