@krisparisian Is OneDrive running on this computer? It might be syncing files or otherwise messing with your user folder. The temporary fix is to pause syncing, which you can do by right-clicking the cloud icon in the lower-right corner of the screen.
If OneDrive isn't the issue, or you can't tell either way, try playing in a new admin Windows account. Make it local, as in, don't link it with your Microsoft account. Test the game once with no mods, just to be thorough, then add fresh copies of a few mods you normally use, ones confirmed compatible with the current patch (1.99). Let me know whether you eventually get the same error in the new account or not. No means a problem with the old account; yes means a more global issue with your system, or a problem with the mods you're using.
@krisparisian Mods shouldn't be corrupted in the run of play. The game reads the files but doesn't modify them, and neither does any other normal process. It's still worth disabling OneDrive, if it's running, in case it's trying to sync your mods and other Sims 4-related files as you play. That could cause all sorts of problems.
If that's not the issue, you may want to run a virus scan. I'm not saying your computer definitely has a virus, only that this kind of odd behavior makes checking worthwhile. Download Malwarebytes (the free trial is fine) from here:
https://www.malwarebytes.com/mwb-download
Open it, click Scan > Custom Scan > Configure Scan, check all the boxes both for all scan types and for all your drives, and let it do its job. This could take anywhere from a few minutes to several hours, depending on the amount of data and whether the scan finds anything., so you may want to set it to run while you're doing something else. Please attach its report so I can take a look.
@puzzlezaddictThey don't get corrupted in the middle of play. I meant that they seem to have a chance of getting corrupted after a play session, so the next time I boot up the game I might get an error about corrupted files. Idk if that detail makes a difference. I did disable OneDrive a while ago.
I considered doing a malware scan before but I wasn't sure if was necessary and I wasn't familiar with free malware scanner apps that were legit. I'll try the scan and let you know how it goes.
Edit: I should add that I haven't gained any more corrupted files since then which is strange. I might just keep booting up and closing my game to see if running it truly is connected to the corruption
@krisparisian Did you remove or quarantine what Malwarebytes found? If so, please let me know whether that helps going forward, or your files get corrupted again.
