nfc-emulate-forum-tag4: 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

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/nfc-emulate-forum-tag4 - from package: libnfc-bin

You may install the required package with command apt-get install {package}
Error in other languages:
nfc-emulate-forum-tag4: bevel nie gevind nie
nfc-emulate-forum-tag4: comandă negăsită
nfc-emulate-forum-tag4: comando não encontrado
nfc-emulate-forum-tag4: commande introuvable
nfc-emulate-forum-tag4: command not found
nfc-emulate-forum-tag4: käsku ei ole
nfc-emulate-forum-tag4: không tìm thấy lệnh
nfc-emulate-forum-tag4: komanda nerasta
nfc-emulate-forum-tag4: Kommando nicht gefunden.
nfc-emulate-forum-tag4: kommandot finns inte
nfc-emulate-forum-tag4: komut yok
nfc-emulate-forum-tag4: nie znaleziono polecenia
nfc-emulate-forum-tag4: níor aimsíodh an t-ordú
nfc-emulate-forum-tag4: no se encontró la orden
nfc-emulate-forum-tag4: no s'ha trobat l'ordre
nfc-emulate-forum-tag4: opdracht niet gevonden
nfc-emulate-forum-tag4: parancs nem található
nfc-emulate-forum-tag4: perintah tidak ditemukan
nfc-emulate-forum-tag4: príkaz nenájdený
nfc-emulate-forum-tag4: příkaz nenalezen
nfc-emulate-forum-tag4: команда не найдена
nfc-emulate-forum-tag4: командата не е открита
nfc-emulate-forum-tag4: 命令找不到
nfc-emulate-forum-tag4: コマンドが見つかりません