If you are getting a specific error code, such as BLZBNTAGT0000138F, you will want to follow and/or post in the Desktop App Mac Technical Support forum:
You can also submit a ticket to Blizzard Support; see https://eu.battle.net/support/en/help/product/services/808/1202/solution . Bear in mind that there are a lot of tickets in the system currently and that the response time is longer than usual. Blizzard Support posted a “Breaking News” about that here .
There might be similar posts on the individual game forums…
The forum here is for providing feedback on the Battle.Net Desktop App; Blizzard rarely replies here.
I have just upgraded to an M3 iMac and although WoW opens Battle.net will not.
As the account is now linked with the new “better” security I cannot play WoW without Battle.net to authenticate me!
Have tried downloading the latest Battle.net but no change.
Is this the big downside of the take over of Blizzard – Mac users will get squeezed out?
Take a look at this topic on the Desktop App Mac Tech Support forum:
Looks like it’s been going on for at least a week now… Blizzard is apparently investigating. There’s a workaround for M1 chipset Macs, but one player reports that that doesn’t work on M3s.
Consider putting a ticket in to at least ensure that Blizzard is aware of the issue for M3s.