txt2pdbdoc: 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/txt2pdbdoc - from package: txt2pdbdoc

You may install the required package with command apt-get install {package}
Error in other languages:
txt2pdbdoc: bevel nie gevind nie
txt2pdbdoc: comandă negăsită
txt2pdbdoc: comando não encontrado
txt2pdbdoc: commande introuvable
txt2pdbdoc: command not found
txt2pdbdoc: käsku ei ole
txt2pdbdoc: không tìm thấy lệnh
txt2pdbdoc: komanda nerasta
txt2pdbdoc: Kommando nicht gefunden.
txt2pdbdoc: kommandot finns inte
txt2pdbdoc: komut yok
txt2pdbdoc: nie znaleziono polecenia
txt2pdbdoc: níor aimsíodh an t-ordú
txt2pdbdoc: no se encontró la orden
txt2pdbdoc: no s'ha trobat l'ordre
txt2pdbdoc: opdracht niet gevonden
txt2pdbdoc: parancs nem található
txt2pdbdoc: perintah tidak ditemukan
txt2pdbdoc: príkaz nenájdený
txt2pdbdoc: příkaz nenalezen
txt2pdbdoc: команда не найдена
txt2pdbdoc: командата не е открита
txt2pdbdoc: 命令找不到
txt2pdbdoc: コマンドが見つかりません