Problem with aireplay-ng

Hello community. I am having trouble when cracking my WEP wi-fi network with Kali.

The steps I follow are:
(say my MAC is CC:CC:CC:CC:CC:CC)

1.- airmon-ng
I get the wlan0

2.- airmon-ng start wlan0
wlan0 gets into monitor mode (mon0)

3.- airodump-ng mon...