multibibliography: 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/multibibliography - from package: texlive-bibtex-extra

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

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