The BN-564 error on consoles can occur when the Overwatch servers are down for maintenance. Please check BlizzardCS on Twitter for updates on server status.
If maintenance is not occurring, please try unlinking your Blizzard account from your Console. Through Account Settings on Battle.net:
- Click Security & Privacy.
- Select Connected Accounts.
- Click Disconnect next to your Console account.
- Close and restart Overwatch on your Console.
To relink your Battle.net and Console accounts, follow these instructions.