Press the RST button (on the side) continuously for 5 seconds to restore ADN-4102 to the default setting. The default IP, username and password are 192.168.1.1, admin and admin.
The ADN-4102 enables all SSIDs (main SSID and multiple BSSIDs) by default. If multiple BSSIDs are not on the Wi-Fi list, please go to Setup -> WLAN -> MBSSID to disable them.