Ok, weird topic, but it's happening on my wife's HTPC. I noticed the other day after the last windows update that the windows security app wouldn't open any longer. First after a bit of panic and some frantic checking I found that the actual anti malware executable was still working and up to date, it was just the UI that was failing. I tried forcing a windows update, nada. so I tried via power shell, nada. Tried resetting the app via windows settings. I tried the SFC /scannow, it did find something, but it wasn't the thing that stopping the UI from updating. I tried the DISM online fix... still nada. There are no other functionality issues with the system. The only thing that I've noticed that stands out is that the sechealthui.exe and other files with it are over a year old, while the ones on my PC are from last month. This issue seems to have started after the last big windows update on her system about a week ago. Any ideas other than a system refresh, I'm saving that one for dead last and maybe not even then as long as it's working.
Edit: I just installed Malwarebytes and it found one tiny thing, but it was only a "suspicious" find and it was in the recycle bin already, nothing else. I'm debating on just paying for a home license and keeping it... opinions?