aux2bib: 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/aux2bib - from package: bibtex2html

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

Error in other languages:
aux2bib: bevel nie gevind nie
aux2bib: comandă negăsită
aux2bib: comando não encontrado
aux2bib: commande introuvable
aux2bib: command not found
aux2bib: käsku ei ole
aux2bib: không tìm thấy lệnh
aux2bib: komanda nerasta
aux2bib: Kommando nicht gefunden.
aux2bib: kommandot finns inte
aux2bib: komut yok
aux2bib: nie znaleziono polecenia
aux2bib: níor aimsíodh an t-ordú
aux2bib: no se encontró la orden
aux2bib: no s'ha trobat l'ordre
aux2bib: opdracht niet gevonden
aux2bib: parancs nem található
aux2bib: perintah tidak ditemukan
aux2bib: príkaz nenájdený
aux2bib: příkaz nenalezen
aux2bib: команда не найдена
aux2bib: командата не е открита
aux2bib: 命令找不到
aux2bib: コマンドが見つかりません