Personally I will delete the folder manually after you close Steam.
steamapps\common\Age of Empires IV\ - delete whole folder than delete C:\Users\your user name\Documents\My Games\Age of Empires IV - whole folder again.
Reopen Steam verify files of AoE4 - it will redownload whole game. Hopefully will fix the folder permissions issue.
A friend of mine is having this issue as well. He is using Windows 11, we’ve tried reinstalling the game, and even reinstalling Windows, and the error persists.
Hey guys took me awhile to figure this one out, so I thought I’d share my fix, especially after the new patch. I am running the game through Xbox Game Pass, but it might work for other launchers as well.
Now if you’re running into this problem like I had, it is because you must allow the controlled folder access to reliccardinal.exe. You can access this under Settings, Privacy and Security, Virus and Threat Protection, Protection History… Should be after failed attempts of opening the game a few protected folder access blockages, click drop down menu on the top right of one of those, will have a pop-up to access, select yes, it now takes you back to that folder access block, should be a drop down “Action” option on the bottom of that folder where you will select “Allow.” Problem solved!
One other thing I did prior were following these same steps, but rather go to Firewall and Network Protection, Allow an App Through Firewall, find CARDINAL on the list, make sure its highlighted blue, select Change Setting with the shield and now you can make it accessible Private and Public, currently mine is on Private only, lastly select Apply.
I hope this helps and good luck if you cannot resolve. I will check back here every once in a while, to help find resolutions if these did not help.
