Since Today you can no longer open both Games at the Same Time.

Black Desert got a small patch today so the Problem does not come from the other game. Please Fix.

bdo updated eac. it now works with apex. 

the Problem does come from the other game, most likely.

I had this same issue and EAC error. I scanned files on the BDO launcher. After doing so and while being logged into Genshin already it let me start up BDO after it finished the scan+patching process. Seems to be steady so far and not throwing the EAC error.

I have the same error. File verification, neither by Steam nor in the launcher, did not help and BDO still crashes at startup whenever Genshin Impact is opened with this error.

There is this same thread like right under this topic... once again. BDO is not at fault. We have the latest version. The other games have outdated versions and thus they won't start at the same time as bdo. Go complain to the other game and ask for EAC update. 

Genshin does not use eac and work with others anti cheat

only eac have a problem with others anti cheat and others versions of eac

EAC started to work correctly, letting BDO to open while Genshin was already running, but looks like with the today's BDO patch the issue is back. Not the first time BDO patch ruins access in some way to its own game. This takes some real talent.

PA updates EAC every week or two to the latest version. If anyone is at fault is the other games for not updating it OR even better, Epic Games for not allowing the latest version of EAC to be used within reasonable version differences. I know, different EAC profiles etc, but some type of tunnel needs to happen on a game-by-game basis. Epic can figure it out and they should.

No problem to get access to BDO. Simply close Genshin. No need to thank me. 

(Joke, joke. Obviously.)