June 25, 2023: According to Blizzard the DDoS attack on Battle.net has been resolved, so it's recommended that you attempt to again.
Diablo 4's servers and the Overwatch 2 shop are down as a Battle.net Blizzard DDoS attack appears to be ongoing, impacting access to different Diablo 4 unable to find a valid license message, that'll be why.
If you're seeing messages in Diablo 4 like "unable to find a valid license," that might very well be because of an ongoing Blizzard DDoS attack. It also looks like the Overwatch 2 shop is down as well due to sporadic reports, although it's currently unclear if that's for the same reason.
"We're currently investigating an issue affecting our authentication servers, which may result in failed or slow attempts," the Blizzard customer for The Americas said earlier today, before adding "We continue to actively monitor an ongoing DDOS attack which is affecting latency/connections to our games [on Battle.net]."
The actual Battle.net launcher provides some more context, as a drop-down message reads "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."
As of publication, it's unclear when Battle.net will be up to full force again, but we at PCGamesN currently get an error message when looking at Diablo 4 on the launcher. The Diablo 4 error code 315306 message as well.
We'll keep an eye out for any updates and let you know if anything changes, but for now, you might struggle to play games on Battle.net like Diablo 4, Overwatch 2, Call of Duty Modern Warfare 2, and Warzone 2.
In the meantime why not check out the best FPS games, if you're missing Diablo 4 and Overwatch 2.