It's bewitched. Ironically for the weekend and on Friday the 13th Battle.net seems to have problems with login. Many players are currently wondering why they can no longer log into their account.
Due to the fact that the Battle.net client itself is affected, all Blizzard games are affected, since you first have to log in to the client to start the games. Call of Duty: Modern Warfare is also affected by the problem and therefore Call of Duty: Warzone is also affected automatically. The Battle Royale mode was only released a few days ago and many players now wanted to fully enjoy the weekend.
Where is the problem?
Blizzard has already become aware of the login problem. Apparently, not all players are automatically affected. Some of us in the editorial office could log in, but others could not. Blizzard commented on Twitter and Battle.net itself:
We are investigating a problem with our authentication servers. Slow or unsuccessful login attempts possible. #BlizzCS
– Blizzard CS EU DE (@BlizzardCSEU_DE) March 13, 2020
According to Blizzard, it's all up to their authentication servers. When the problem will be fixed is not yet known.
Can you get around this?
There are some users on Twitter suggest the possible workarounds. Accordingly, it is probably possible to start WoW at least via the exe files in the installation folder. The Battle.net launcher is used in principle.
As I said, this only works with WoW. If you just want to play Warzone and can't log in, you'll have to wait for a Blizzard fix.