What to do when a physical authenticator gets out of sync

What to do if you corrected your country of residence in your account details but still you can't add your phone number to your account

Blizzard servers could not be reached or may be offline.

Instructions on linking your MLG and Blizzard accounts

What to do if a friend or family member has access to your account and has updated the account details, are preventing you from accessing the account, or has taken gold or items.

This error occurs when the Battle.net Setup program does not have permission to install the game on your computer.

Information on error BLZBNTAGT0000084A

Information on error BLZBNTAGT00000846

Information on error BLZBNTAGT00000849

Attempting to play Diablo III results in error 3007 or 316704