You might have been impacted by the recent DDoS attack on Diablo IV, with the soul-crushing error messages of not being able to log-in. Well, Blizzard is well aware as a recent Battle.net customer service account tweeted out about the issues with Diablo IV.
The account tweeted: "we are investigating the login issues affecting Diablo IV and working to resolve these as soon as possible. Players may experience queues while we work on the issue". We had confirmation of the DDoS attack on Diablo IV shortly after, with the account tweeting: "we are currently experiencing a DDoS attack, which may result in high latency and disconnections for some players. We are actively working to mitigate this issue".
[#D4] We are investigating the login issues affecting Diablo IV and working to resolve these as soon as possible. Players may experience queues while we work on the issue.
— Blizzard CS - The Americas (@BlizzardCS) June 25, 2023
The account has most recently tweeted that the "DDoS attacks that we were monitoring had ended". Personally, I can log in now but couldn't for many hours last night. I shifted over to Overwatch 2, and then my brother tried to change accounts and couldn't log in to his other Battle.net account, as the authentication servers were having issues.
#Bnet The DDOS attacks that we were monitoring have ended. If you are still unable to log in try https://t.co/NY39q2slWo
— Blizzard CS - The Americas (@BlizzardCS) June 25, 2023