txt2png: 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/txt2png - from package: dvdwizard

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

Error in other languages:
txt2png: bevel nie gevind nie
txt2png: comandă negăsită
txt2png: comando não encontrado
txt2png: commande introuvable
txt2png: command not found
txt2png: käsku ei ole
txt2png: không tìm thấy lệnh
txt2png: komanda nerasta
txt2png: Kommando nicht gefunden.
txt2png: kommandot finns inte
txt2png: komut yok
txt2png: nie znaleziono polecenia
txt2png: níor aimsíodh an t-ordú
txt2png: no se encontró la orden
txt2png: no s'ha trobat l'ordre
txt2png: opdracht niet gevonden
txt2png: parancs nem található
txt2png: perintah tidak ditemukan
txt2png: príkaz nenájdený
txt2png: příkaz nenalezen
txt2png: команда не найдена
txt2png: командата не е открита
txt2png: 命令找不到
txt2png: コマンドが見つかりません