starconvert: 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/starconvert - from package: starplot

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

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