wdf-cat: 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/wdf-cat - from package: wit

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

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