vbvolregress: 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/vbvolregress - from package: voxbo

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