So I don't completely understand all your questions, I don't know how or where to look for those files you're requesting. I usually just don't touch anything because I don't want to create problems. What initially happened was I was not able to open or play the sims at all about a month ago after it told me to download the update. I tried all the troubleshooting tips and it didn't work so I jusg left it for a couple weeks. Then the game started to work as normal for a few sessions, up until it recently asked me for another update.
Now what happens is I will be playing for a bit and send my sims to school and to work as normal, but then I'll have to exit out of sims for the day because of I have a lot of work responsibilities. I only end up being able to play for an hour or so a few times a week. The next time I log back into my game, when they were in the middle of school or work, they just suddenly arrive home and I get a notification saying they're done with class or work for that day. Because it cuts off their school/work day, the game treats it as if they're "playing hookey." So their performance goes down. I've also noticed now that when I send them to school and work, their performance bar doesn't change at all, it neither increases or decreases, no matter if they've completed all daily tasks, are in a good mood, and have the "work hard" option on. This happens across all ages, all careers, and all types of schooling. It even happens when the child sim goes to a scout meeting and her performance isn't increasing despite the fact she's collected all the badges and is still not advancing to the next level.
Also no I do not use any mods or stuff like that. And I guess these aren't for any active jobs. The one sim is in tech guru, the other sim is in entertainment as a comedian, and the child is in school and the scouts club. I also don't have that expansion pack for school or whatever it is called, so it shouldn't be doing this. I've just had continuous errors whenever the sims release an update or whatever, and I'm regretting my decision to even buy expansion packs when it's now feeling like a waste of money if I can barely play the game without incurring some sort of bug/error.
And like I said, I also don't want to go meddling around deleting files because I'm worried I will delete any saved content I have or do something seriously wrong to my game.