Bn-564 error is an issue that Overwatch players on PS4 have been facing. If you or some of your friends are facing this too then don’t worry we got you covered.
If the game’s not undergoing maintenance or server issues, then the problem lies with your account connection. To fix this you need to un-link your Blizzard account from the PS4. To do this go to Battle.net, click on “Security & Privacy”, choose “Connected Accounts” and click “Disconnect”.
Now if you restart Overwatch on your PS4 the problem should have been fixed. Piece of cake right?