odt2rtf: 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/odt2rtf - from package: unoconv

You may install the required package with command apt-get install {package}
Error in other languages:
odt2rtf: bevel nie gevind nie
odt2rtf: comandă negăsită
odt2rtf: comando não encontrado
odt2rtf: commande introuvable
odt2rtf: command not found
odt2rtf: käsku ei ole
odt2rtf: không tìm thấy lệnh
odt2rtf: komanda nerasta
odt2rtf: Kommando nicht gefunden.
odt2rtf: kommandot finns inte
odt2rtf: komut yok
odt2rtf: nie znaleziono polecenia
odt2rtf: níor aimsíodh an t-ordú
odt2rtf: no se encontró la orden
odt2rtf: no s'ha trobat l'ordre
odt2rtf: opdracht niet gevonden
odt2rtf: parancs nem található
odt2rtf: perintah tidak ditemukan
odt2rtf: príkaz nenájdený
odt2rtf: příkaz nenalezen
odt2rtf: команда не найдена
odt2rtf: командата не е открита
odt2rtf: 命令找不到
odt2rtf: コマンドが見つかりません