I have had this issue since the 06/08 and Didn’t do anything due to work hours.
On the 15/08 I still got the error code, and reach out to blizzard, they sent me some trouble shooting and that still does not work, I have uninstalled and re downloaded the game and battle net serve more than 5 times over the few weeks. I haven’t had an issue until this patch, all my other games work perfectly fine steam account is good, no issue. I believe you have a bug.
Its coming to the point I am just willing to complete cancel my account and not even re download it coz i am kind of over it