cub2pngs: command not found

Have You tried accessing the binary with the full path?

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/lib/voxbo/bin/cub2pngs - from package: voxbo

You may install the required package with command apt-get install {package}
Error in other languages:
cub2pngs: bevel nie gevind nie
cub2pngs: comandă negăsită
cub2pngs: comando não encontrado
cub2pngs: commande introuvable
cub2pngs: command not found
cub2pngs: käsku ei ole
cub2pngs: không tìm thấy lệnh
cub2pngs: komanda nerasta
cub2pngs: Kommando nicht gefunden.
cub2pngs: kommandot finns inte
cub2pngs: komut yok
cub2pngs: nie znaleziono polecenia
cub2pngs: níor aimsíodh an t-ordú
cub2pngs: no se encontró la orden
cub2pngs: no s'ha trobat l'ordre
cub2pngs: opdracht niet gevonden
cub2pngs: parancs nem található
cub2pngs: perintah tidak ditemukan
cub2pngs: príkaz nenájdený
cub2pngs: příkaz nenalezen
cub2pngs: команда не найдена
cub2pngs: командата не е открита
cub2pngs: 命令找不到
cub2pngs: コマンドが見つかりません