Unable to access the game, getting error WOW51900104 when attempting to log in

What to do if you can't login to Warcraft Rumble due to error "Failed to Create Popup For ClaimPendingReward, PlayerProgressionServerError"

Troubleshooting login timed out for Diablo IV

Troubleshooting steps when you can log into your account management page but not the Battle.net App

What to do if you receive the "Login Failed" error after you applied a character service.

Your login session has expired. Please log in again.

This message is displayed when no Overwatch license is on an account. Ensure you are logging into the correct Battle.net account.

​The authentication service is currently experiencing a high volume of traffic. Please try again later.

Troubleshooting errors when trying to sign in to our forums

How to resolve this error when trying to log in to Battle.net