Network is down

[All3xJ]

After started the program and set the interface, it seems to work at the beginning showing essids of wifi networks, but then:

Traceback (most recent call last):
  File "wifijammer-ng.py", line 485, in <module>
    main()
  File "wifijammer-ng.py", line 481, in main
    jammer.jam()
  File "wifijammer-ng.py", line 126, in jam
    sniff(iface=self.mInterface, filter=filter_string, store=0, prn=self.cb)
  File "/usr/lib/python2.7/site-packages/scapy/sendrecv.py", line 767, in sniff
    p = s.recv()
  File "/usr/lib/python2.7/site-packages/scapy/arch/linux.py", line 600, in recv
    pkt, sa_ll = self.ins.recvfrom(x)
socket.error: [Errno 100] Network is down