This problem may occur if you have entered an incorrect password for your home Wi-Fi network during registration process. To change it please open Settings menu in the Petcube app, scroll down to Wi-Fi and follow the instructions on setting up the connection again.
In case it doesn’t help, your Wi-Fi router may be set up to transmit in WEP encryption mode which is not supported by Petcube Camera. Petcube Camera works with newer WPA/WPA2 encryption technology that aims to provide stronger wireless data encryption than the WEP encryption. To fix this please go to router settings in your web browser and change the encryption mode from WEP to WPA/WPA2. You may need to contact your ISP to be able to do that.