Hello Fernando,
What firmware version is the AP running on?
Can you SSH into it and do you have the login credentials? If you are able to console or SSH into it then please follow these instructions to default the config:
How to factory reset the config of a WiNG AP or controller from CLI
To reset an AP using the discovery tool, it should not have been up for more than 10 minutes. Reboot the AP and try again. You will need the serial number of the AP.
SSH into this AP if possible and run the following command to determine which AP is the controller should you need this information:
>en #show adoption status I hope this helps,
Regards
Chris
Christoph S.