Breathe: nothing below deletes anything. Here is the triage volunteers do by hand on Sims Discords, in order — from the cheapest move to the most expensive. Stop as soon as a step explains your breakdown: going further would send you looking in the wrong place.
Before touching anything, copy your Mods folder somewhere else — the desktop, an external drive, anywhere. It takes two minutes and it makes every step below risk-free.
This is the most common mass breakdown, and the fastest to fix: the game unchecks mods at every patch. In game: Options → Other → tick "Enable Custom Content and Mods" and "Script Mods Allowed". Then quit the game completely and reopen it: the change only takes effect on restart.
It looks too simple to be the cause: yet this is where experienced helpers most often miss it and recommend a full reinstall instead.
Three mechanical traps, and the game stays silent in all three. An archive (.zip, .rar) left as is never gets read: the game doesn't look inside, you must extract it. A .ts4script file only goes one subfolder deep — any deeper and it doesn't exist for the game (.package files can sit lower). And the Resource.cfg file at the root of Mods: if it was renamed or emptied, no .package loads at all; delete it and the game recreates a healthy one on next launch.
A telltale sign: the game calls a file "corrupt" and it's a different file every time. The cloud kept the contents online and left only an empty stub on disk. Don't delete anything: Windows/OneDrive → right-click Mods → "Always keep on this device". Mac/iCloud → right-click → "Download now", then turn off "Optimise Mac Storage".
While those stubs exist, the elimination search in step 6 cannot converge: the set being tested changes between two attempts. Fix this first.
The harmless move, and the only one on this page that erases anything — but something the game rebuilds by itself. Delete localthumbcache.package, at the root of Documents → Electronic Arts → The Sims 4. If the EA launcher is misbehaving (crashing startup, empty store), clear its cache too, from the EA app: Help → App Recovery → Clear Cache.
Look at the root of Documents → Electronic Arts → The Sims 4: a lastException file often names the mod at fault. Two details that save hours: a lastUIException report is about the interface and cannot incriminate a script mod; and a freeze or a hard crash writes nothing at all — the game only logs errors it catches. No report doesn't mean no culprit.
The last resort, and it has to be earned: only start it if nothing above explained your breakdown. Begin with the blank test — rename your Mods folder to Mods_off and launch the game. If it runs fine, a mod is at fault: put half your files back, relaunch, watch, then repeat on the suspect half. Eight relaunches are enough for two hundred mods.
A shortcut that saves hours: if your game freezes in build mode when you type in the search bar, start the elimination with your build and buy content. It's a case the community knows well, caused by broken CC — often old, and still downloadable somewhere. It has nothing to do with a recent patch.
Two warnings. If the problem persists with no mods at all, it comes from elsewhere — the game, a save, a cache. And content still used by your save that vanishes during the test can produce bald Sims or missing furniture: that's normal, and putting it back fixes it.
It deals with what breaks your game, not with what makes your save annoying: a mod with questionable gameplay choices is not a breakdown. It also can't help with missing purchased content — that's EA support — nor with a copy of the game obtained outside EA. And if everything above is in order, the cause is elsewhere: this guide won't invent it.
This guide is free and will stay free, even if you never install anything. If you'd rather have all of this done for you — and the faulty file named instead of guessed — that's exactly what Bedside does.
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