Heyo!
Looks like Easy Anti-Cheat is erroring out because those certificates have expired, and it cannot find them to update them. What you should try, is going to the control panel and UNISTALLING the Apex application AND the Easy Anti-cheat. You will then have to reinstall both.
When you got prompted by the Untrusted System File, that’s almost certainly simply Windows alerting you that the file came from an external source. (I.E. you did not create it), and that you need to give it permission to run.
The reason Anti-cheats often end up triggering this warning is due to how they run on a similar level to system operations, which is also where viruses attempt to run.
If you trust Respawn and EA to not be vending malware, you should allow permissions to run when prompted again.
The error changing is based upon it checking various possible save locations. The reason generic repairs and reinstalls probably don’t work is because it doesn’t realize the downloaded Anti-cheat is incomplete.
TLDR;
Basically, you deleted the “ID badge” of the security software for the game. You need to repair/reinstall to replace the missing files. When prompted, you need to give the low-level application permission to run, do so at your own volition.