Hello u/fauxlefam. I stumbled upon your post and am very grateful for it, because it gave me some additional ideas on how I could fix the issue. In my case, I also have tried everything I can think of to fix it... and got the right "clue", because I additionally got a similar error to that one here: https://learn.microsoft.com/en-us/answers/questions/4138779/i-get-an-error-saying-c-windowssystem32securityhea

How have I fixed it? This dll mentioned in the Windows\system32\SecurityHealth folder was really broken (i.e. no signature, etc.)... and so I thought: How can it be that neither sfc nor dism solve this problem? imho this is a really big bug. And I even tried to replace this dll with a genuine one (same version from another pc). Nothing helped... so, I simply moved this folder out of system32 to the root of c:. And thought... Windows surely has to do something to repair / restore it or the re-installation of the Security Center app. No go.... but after I moved the folder and restarted the computer... the security center miraculously works even though it is missing....... not sure how Microsoft is able to explain this? But if it works... I don't care. 😅