sphinx_lm_convert: 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

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/sphinx_lm_convert - from package: sphinxbase-utils

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