After the latest update, I have been experiencing this dreaded error code. I was in Helltide and suddenly lagged out, kicked out the game and haven’t been able to log in since. I tried restarting my router, my PC, re-installing BattleNet, updating drivers, etc and nothing works.
Edit: After 3 days of constantly trying to log in, I finally made it. I didn’t change a thing, it would seem BattleNet has a mind of its own.. Thank you Blizzard /s