Here is what I got from that:
Current WiFi configuration
SSID: Arduino Yun-90A2DAF80A4A
Mode: Master
Signal: 0%
Encryption method: None
Interface name: wlan0
Active for: 1 minutes
IP address: 192.168.240.1/255.255.255.0
MAC address: 90:A2:DA:F8:0A:4A
RX/TX: 0/3 KBs
Not sure if it would help to post the log from the YunSerialTerminal sketch?