texifylex: 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/texifylex - from package: texify

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