convbkmk: 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/convbkmk - from package: texlive-lang-japanese

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

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