xsec-txfmout: 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/xsec-txfmout - from package: xml-security-c-utils

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