This issue seems to be caused by pausing the game before a loading screen and saving before the GUI has fully loaded. There might also be a tie in to other events going on. Play the event without any scenarios and don't play residential rentals. I would also avoid visiting DU community lots that have events going on as well as residential rentals while you are doing the event.
Do not pause the game before or after a loading screen (travel, CAS, turning off the game) and wait until the GUI and especially the tasks have fully loaded before you engage with the game.
If you are using MCCC or other mods that pause the game automatically, turn off these features or remove the mods if that's all the mod does.
If you are using Better Build Mode, make sure to turn of organized Debug. That also causes issues.
More info on incompatible mods can be found here: https://www.patreon.com/posts/mods-and-grim-112712201
If you are already stuck, try the steps below (there is currently no workaround for console)
User folder can be found here: Documents>Electronic Arts>The Sims 4
- Create a backup of your user folder to a external drive/thumb drive or a different place on your hard drive outside the Electronic Arts folder,
- Move your mods folder to the desktop (I'm going to leave this step in but if you are a confident mod user and have turned off the parts that are causing issues, you can leave them in)
- Delete the localthumbcache file (this is a cache file that recreates itself)
- Move accountDataDB.package to the desktop (this WILL affect your happy home login rewards but you can get them back after you done the event (see below))
- Repair your game through EA app/Origin/Steam
- Start a NEW save game. This is important because you won't have your mods cc. I would still start a new save even if you leave them in.
- See if it now works for you.
To get your happy Home rewards back
EA will add the Happy Home Login Awards to base game next week. If you aren't dependent on them until then, you can just skip this part.
- Once you finish week 1, copy the new accountdatadb.package to a different place (not your desktop as you already have a file there)
- Copy the accountsdatadb.packge from your desktop back to your sims folder.
- Start the game and check if the reaper event still shows as done and if you have your rewards.
- If you do, check if you have your happy home rewards back
- If you have everything back, you can delete the two copies you made of accountdatadb.package (not the one in your user folder)
As an alternative for your happy home rewards: If you have a backup from usersetting.ini from BEFORE Patch 1.109.185, you can also try copying that back.
Once you have done the event, you can put your mods back and play your regular save. You should be able to buy everything you earned. I do encourage backups.
You can also find some more info in my blog post: https://sims4.crinrict.com/eng/2024/09/reapers-rewards-event/
Other Issues
Thread for missing Happy Home rewards: [NEEDS INFO] Happy Login Rewards removed (Patch 1.99)
EDIT: EA announced a patch for early next week to address some of the issues. I hope this is part will get fixed. Because of this, I'll wait with further individual help till then.