otl2html: 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/otl2html - from package: vim-vimoutliner

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

Error in other languages:
otl2html: bevel nie gevind nie
otl2html: comandă negăsită
otl2html: comando não encontrado
otl2html: commande introuvable
otl2html: command not found
otl2html: käsku ei ole
otl2html: không tìm thấy lệnh
otl2html: komanda nerasta
otl2html: Kommando nicht gefunden.
otl2html: kommandot finns inte
otl2html: komut yok
otl2html: nie znaleziono polecenia
otl2html: níor aimsíodh an t-ordú
otl2html: no se encontró la orden
otl2html: no s'ha trobat l'ordre
otl2html: opdracht niet gevonden
otl2html: parancs nem található
otl2html: perintah tidak ditemukan
otl2html: príkaz nenájdený
otl2html: příkaz nenalezen
otl2html: команда не найдена
otl2html: командата не е открита
otl2html: 命令找不到
otl2html: コマンドが見つかりません