Apex won't launch due to steamclient64.dll

same issue after steam update !.

I have a ticket support in EAC meanwile downloading Origin version.

EAC dont have that new dll of steam and have that issue.

I have the same issue,Tried repairing local files, tried repairing then reinstalling easy anti cheat,updating steam,my antivirus,stopping my anti virus for a second nothing worked

Following this. Played earlier just fine until now, don't know what the issue is.

Also having the same issue cant open apex

EDIT: I seem to have found a fix

1. make sure your steam is completely closed

2. go to C:\Program Files (x86)\Steam\steamapps\common\Apex Legends\EasyAntiCheat or wherever your game files are located

3. delete the certificates folder

4. run EasyAntiCheat_Setup.exe and select apex legends and repair service

5. try running apex again

This is what worked for me for now at least

pretty sure that 

Untrusted system file
Files: steamclient64.dll

and "optional parameters"  (-steam -eac_executablename "R5Apex.exe")

Are actually two different issues.

1. new steam client isn't in the anti-cheat white list yet 

2. new steam client has a bug that is registering the default params as extra optional params.
     then when you click "ok" it accepts them and the re-wraps with the default params again so you get
     '-steam <approved optional params> -eac_executablename "R5Apex.exe"'
     aka '-steam -steam -eac_executablename "R5Apex.exe -eac_executablename "R5Apex.exe'

Edit:
My bro ran into this first, I was able to play apex through steam fine but downloaded the new steam client to confirm that that would give me the same issue. it did.

you can appease the anti-cheat by deleting the specified file (steam will reinstall it on restart) but I don't have a work around for the issue with approving the "optional parameters".

Edit 2: Bro can launch via origin without issue, just not via steam.

same thing happening to me, verified files, deleted steamclient64.dll, nothing works. I was playing today everything ok but after steam update game won't run

Same issues with mine, went through all of the steam repair options, but no dice. 

So Ive been doing a bunch of research on how to fix this, however it seems like none of it is working.

What Im assuming the problem is is that Apex does not recognize the new version of steamclient64.dll, that or the Easy Anti Cheat has not been updated to recognize this version of the game. Im assuming that since the anti cheat doesn't recognize this version, it does not want to ruin it incase of the potential of it being a mod/hacking software. Again only my assumption.

The easy solution is just to download the game through origin, it should work just fine.

Here are the things I have tried thus far, none have not worked so I don't recommend using these unless you want to try and find more answers, I'm just listing things I've done so they don't need to be repeated. Again I don't recommend doing these things to expect it to work, but it may work for the very small minority.

-Reinstalling Graphic card version

-Tried running in Clean boot

-Replacing the steamclient64.dll with an older version of it (steam auto update replace it anyway, maybe there might be a solution around this but I could not find out how, might be against TOS for tampering but again I don't really know.

-Verify Game file integrity

-Tried running in Dev mode

-Reinstalling Easy Anti Cheat

-Tried running without Easy Anti Cheat

-Repaired Easy Anti Cheat

-Ran my Pc with Easy Anti Cheat Disabled while installed

If you guys find anything else that may potentially work let me know, Ill see if it works.