Failed to save/Unable to create system data?

[blind_spectre]

A few days ago, I was playing Persona 5 Royal and I suddenly had an issue with my game being unable to save. Whenever I try to change the settings, I would get a pop-up saying "Failed to save system data" and whenever I tried to save the game itself, I would get ones saying "Failed to complete save," the system data message again, and "Failed to save." Trying to play a completely new save has the same result. I tried removing all my saves (system and game) and when the game tries to make new system data, it says "Unable to create system data."

I became aware of this issue on March 22nd. The last time I had played it before this was around March 12th and it had been working perfectly fine then. The only thing I can think of that has happened in that time was that I had a Windows 10 update (wouldn't be surprised if that was the issue, but I hope it isn't because I'm not sure how I could fix that).

I have disabled all mods, uninstalled Reloaded-ii, verified the game files, disabled cloud saves, uninstalled and reinstalled P5R, uninstalled and reinstalled Steam outside of Program Files, ran as administrator, created an exclusion in Windows Defender, and my user account doesn't have any non-english characters in it. From what I checked, my processor supports AVX and SSE4.2.

Sorry if this is too much, but I've tried everything I can think of and everything I saw suggested on posts people have made about similar issues, and nothing is working. I'm at a total loss and think I may be ♥♥♥♥ outta luck, but I'm trying to ask around anyway in the hopes that someone can help

[blind_spectre]

I FIXED IT!

So apart from my issues with P5R, Windows was having issues as well with installing updates and such. Today I decided to do something I should have done in the first place and looked up the error code it was giving me, and found this[answers.microsoft.com]. Trying the first suggestion (resetting the File System Resource Manager) fixed both the Windows issue AND the Persona issue!

For those that don't want to click the link, here's what I had to do:
1. Right-click on Start then click on Command Prompt (Admin)
2. Paste this command and press Enter:
fsutil resource setautoreset true C:\
3. Reboot PC

I think this also fixed the sudden problem with lag I was having with P5R as well, but I'd have to play more than just a test run to be sure. I'll leave these here in case it helps someone else!