espctag: 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/espctag - from package: espctag

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