bsetbg: 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/bin/bsetbg - from package: blackbox

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