What to do if you think another person or group of people has targeted a DDoS attack on you
Troubleshooting steps for disconnection problems with the Battle.net mobile app
You have attempted to connect to an invalid server. If this problem persists, please contact Customer Support.
Troubleshooting for the "Playful Sprites" error in Hearthstone.
What to do if you are stuck at creating a game
How to troubleshoot connection issues to World of Warcraft Classic or Wrath of the Lich King Classic