I had this problem and found a way to fix it.
After destroying the book, your sim gets a specific debuff that lasts ~2 days. (Using a moodlet solver or potion of emotional stability will remove the debuff but NOT the effect of randomly starting fires all the time. I think this is how my sim got bugged, because I used moodlet solver; however, since for a short time there was the bug where reloading the game would remove all moodlets, I'm guessing many people got bugged this way.)
(Click the spoiler to expand several paragraphs detailing my crumbling sanity as I tried to figure out how to fix this alone, or skip down to get straight to OMG FIX IT WTF...)
The problem is, there is a hidden commodity tracker that counts down until the next fire goes off, resets, counts down again, starts another fire, etc. This countdown repeats until the cursed debuff runs out on the sim; however, it seems any means of removing the debuff early will NOT stop the repeating hidden countdown. (RPO mod has a very detailed sim info viewer that let me read the entire list of tracked commodities. There are TONS. The game is constantly tracking hidden timers called "commodities" for everything, from the "diaper fullness: <amount>" to "time since last sleep: <amount>", etc. etc. etc. I realized the offending commodity is called "commodity_muEvent_Cursed_StartFire" and that Value is a HIDDEN, burning doom-o-meter.
What it should really be called is "COUNTDOWN TO NEXT RANDOM OBJECT, (with preference to objects that can't usually burn, LIKE A CEILING LIGHT! How fun!) SPONTENEOUSLY COMBUSTS and wakes up all 4 toddlers and 2 infants AGAIN."
It was absolutely driving me crazy...so I spent a few hours researching the issue and a few more DEEP DIVING under the hood of "what makes the sims...like...everything." I learned what commodities are and how they usually work, then spent a long time analyzing EVERYTHING ABOUT MY ACTIVE SIM...
I read the lists of buffs, traits (including hidden), stats, every single attribute the sim has, and finally found this suspicious commodity. I idled at home, checked the commodity a few times, observed the change in Value, observed yet another random unreachable fire...and that's how I learned this BLACK HOLE WHERE HAPPINESS GOES TO BURN AWAY was somehow orphaned on my sim.
I researched a LONG time trying to figure out how to just remove or delete the particular commodity tracker but couldn't find anything.
I learned a lot while obsessively trying to rid myself of the "fun incinerator". This commodity is one of several that form a TANDEM PAIR (both, TWO, ( 2 ) in tandem, a pair, etc.) and work together to form various "action yields consequence" types of gameplay.
Essentially, this tandem pair *should* work like so: Commodity A exists. Thus, Commodity B also exists until Commodity A is gone. Commodity B repeats a countdown to start a fire, then begins the countdown again until commodity A doesn't exist anymore. Then BOTH cease to exist.
Unfortunately, the cursed debuff is gone and THIS ORPHANED COMMODITY (which should REQUIRE its tandem partner to exist at all) is here.
It's unsupervised, persisting without its partner, and this commodity is a manic, immortal, never sleeping, TERRORIST ARSONIST.
Fascinating...
I WAS DESPERATE TO STOP HAVING FIRES. The last straw was the OCCUPIED INFANT CRIB. In the middle of the night, the occupied crib burst into flames in a nursery with NO LIGHTS ON, NO CANDLES, NO FIREPLACES, NO...ANYTHING. And the entire house was asleep so it couldn't be ANYTHING ELSE BUT THIS COMMODITY THAT WILL APPARENTLY PERSIST FOREVER UNLESS I FIGURE OUT HOW TO REMOVE IT.
My last shred of sanity formed one glimmering spark of an idea
as... I...
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further
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into this kindling madness...
I FIXED IT.
I used MCCC (mccc > cheats > cheat sim info > mood/buff control > add buff) to manually add the cursed debuff BACK ON my sim, as if I had just finished the event by destroying the cursed book on my lot.
(It's called "Cursed!" and the icon is a book on a fear (purple) moodlet.)
I took the newly-re-cursed sim AWAY FROM the HOME LOT and ran the timer out on the debuff. (It doesn't *seem* to set fires on community lots, so I spent the entire ~2 days debuff at parks/libraries/etc. I didn't have a single fire start at any of the community lots that I loitered around while waiting for the 2 days to pass. YMMV.)
Once the debuff expired naturally, the hidden commodity tracker was also gone (which I confirmed, again, using RPO's option to view all sim information then clicking the list of commodity trackers.) No more random fires!
@LadyXelda That's interesting. Thanks for sharing.
Wonder what else could have got the timer stuck cause there are reports from way before the moodlet bug. Guess would be interesting to know if they used potions.
Could you add the exact cheat you used ? Guess you'd need allcheats/mccc to add it back,
For console players it might work to have the event again.
From what I saw is that the events are totally random so if you get an event in your rental unit, save under a new name and reload the game. This should give you an event but a different one. Repeat until you get cursed book.
