If you tried the web-based and software client setup methods in How do I set up my Fitbit device? and you're still having difficulty, try setting up your Fitbit Aria using a phone.
From your phone, visit our setup page to get started. Once Aria is set up, your scale will automatically sync to your Fitbit account using your router, and you no longer need the phone to sync your Aria to your account.
If you're trying to set up your Aria again after making changes to your network, see How do I reconnect my scale to my wireless network?