I'm trying to execute a wash command but it freezes. These is the output:

root@kali:~# wash -i mon0

Wash v1.4 WiFi Protected Setup Scan Tool
Copyright (c) 2011, Tactical Network Solutions, Craig Heffner <cheffner@tacnetsol.com>

BSSID                  Channel       RSSI       WPS Version       WPS Locked        ESSID
Could you help me please?
Many thanks and sorry for my english!