You cannot put foul fish in the fridge in The Sims 4. The game doesn’t allow you to store fish that has gone bad. Fish needs to be fresh for you to store it in the fridge.
If you can’t put fish in the fridge, this indicates the fish that your Sims caught has already gone bad.
If you do manage to put fish in the fridge, it still goes foul after 1 or 2 Sim days. Raw fish doesn’t last very long in the refrigerator.
You can’t prolong its freshness indefinitely, unlike other types of food which can last for weeks before going bad.
You’re better off selling it while its quality is still excellent. You can also use the fish that your Sims have caught to cook delicious dishes.
If your fish is of excellent quality and you suspect this limitation is actually a glitch, try traveling to a different lot, exit your game and come back.
If you’re using mods and CC in your game, move your mods folder to the desktop. Restart The Sims 4 and check if you can store your fish in the fridge.
You can also delete the localthumbcache.package file from your The Sims 4 folder.
If the issue persists, repair your game files. Open your Origin Library, right-click on The Sims 4, and select Repair Game.
Hope something helps.
⇒ Quick Tips:
Fish is one of the best fertilizers in The Sims 4. Even if it’s gone bad, you can still use it successfully to grow Excellent-quality plants.
Keep in mind that vegetarian Sims cannot eat fish. If they do, they’ll feel nauseous for a few hours. The same is valid for Sims with the Child of the Ocean trait.