uykud7nxc5o3 No lights and almost no cooking ability really sounds like you have the Off the Grid challenge stuck on. The only thing you can cook are salads or, if the stove is rated for OTG, a few other meals. You did say you turned the Simple Living challenge on and off, but I got the impression you didn't do that for Off the Grid. So, if you haven't, try that. You could also place a few candles around to see if that will give you any light.
But, tbh, since it affects any other lot you play, I think it's something non lot specific. So, I suggest you create a new user folder by moving or renaming your current The Sims 4 folder and start the game again. After you place the obligatory sim, check to see if you have power and can cook. If things are not ok then the only thing left that I can think of for you to try based on what you've said above is a complete uninstall/reinstall. If everything is fine, then quit without saving and then copy your original saves folder over to the new user folder. Start the game again and check if your sims have lighting and can cook again. If they do, then quit without saving and copy over your mods folder and test again. If everything is still ok, then copy over any other folders like custom music, screenshots, overrides, etc. and then see if the game is still ok. If it is, you are good to go. If things are still messed up when you test at any point, then the problem is in the save itself and you might have to abandon the save (hopefully not).
Hope this helps.
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