Out-of-date drivers and operating systems can cause a variety of issues, and are one of the first things to check when a game is having problems.
Information on error BLZBNTAGT00000840
Troubleshooting steps for disconnection problems with the Blizzard mobile app
How to view your friend's wish list.
Troubleshooting for issues loading the BattleTag or Real ID friend list
This error may happen when something interferes with the uninstall process.
During technical troubleshooting, it is sometimes necessary to fully uninstall and reinstall a game.
Information about troubleshooting problems with the Blizzard Battle.net friends list
Steps on how to close down background applications and processes.
If you encounter a bug in one of our games, please report it to us.