Items stuck in personal inventory

@Mornimras Are these items in the sim's personal inventory or household inventory? It sounds l like some items may have gotten bugged. You can try resetting the item, if you can place it in the world. You can also try a game repair. Can you share a screenshot if the following doesn't work?

Items in personal inventory:

• Some items are not deletable in the personal inventory and you have to click the item and tell the sim to clean it up, etc.
• Sometimes an item cannot be sold in their inventory but can be destroyed (if you have that option) or gifted to another sim.
• As I'm sure you know, some items can be dragged onto the floor or counter, then in live mode or BB they may be able to be dragged to trash, added to household inventory, deleted with the sledgehammer, incinerated if you have a spellcaster, etc.... you get the idea. But this may give additional options. If worse comes to worse, you could add the item to a room in the yard and delete the room along with the item.

Items in Household Inventory:

• I assume your tried this, but can you drag the item to 'Sell'?
• Can you place the item in the world as I mentioned above and try the things I mentioned to delete it?
• You can see if there are any other options for the item.

Some more harsh things to try (you can just cheat them the funds to make up for any financial losses when you're testing)....

• If you move the sim or household to a new lot, some items may be reset in the process. You can just cheat them the funds to make up for any financial losses when you're testing.
• If that is not enough to reset/delete problematic items, you can try saving the sim with the issue into your library, place them into the game. This will sever any relationships they had.
• If that is not enough to reset/delete problematic items, you can try saving the household to your library (this will preserve relationships only with the sims saved with them to the library in this one household), then re-place them in the game.

Edit: You can also try using multi-select and sell to see if it allows you to sell items you weren't able to individually.  If you own EL you may be able to recycle some items.

Thank you for the tips !

i  made a short video showing what’s exactly is happening .

https://drive.google.com/file/d/1JqUGu2NsrJDu1hKM8qc5PC93DXBIEKC1/view?usp=drivesdk

when i place object in the world trough command it just stays there  and tells me the sims do not own this item, and it stays there .

the worst part is for consumables , since they stack and behave the same way. 
t happened before they moved out of the lot , I didn’t really pay too much attention back then 🫣 but in my main lot I’m cleaning up inventories every night cause otherwise there’s a lot of spoiled eggs and milk 😂.

I have not thought about gifting items to another sim , just tried fhat and in the recover inventory the items behave like they supposed to.

as for further tips , since that’s a legacy game and further relationships are essential uploading to the gallery is not an option . They are to far in . 

@Mornimras Thank you for the video, as it was helpful.

• I didn't mean to save them to the gallery... I mean the the library in your game. But yes, if maintaining the relationships is essential you do lose all relationships except the ones in the household you were loaded into the library with, so that's an important factor. 
• If you move the sim out that can delete some things, but this varies.
• Yes, if the item belongs to someone else, or has become 'unowned' it will give you hassles. Maybe you can gift them to an employee... like your maid, gardener, butler, or someone you invite to the lot?
• I did forget to mention that... If you have something spoiled in a stack you have to delete or clean up or whatever option you have for the spoiled items in the stack before deleting the stack. (Such as spoiled eggs, spoiled fish, etc.)

So, by looking at this image I am assuming that you're dealing with personal inventory. Did you try seeing if it would let you include the items if you have muiltselect enabled? 

You could purge this sim's personal inventory via a cheat... First, remove everything from her personal inventory that you want to keep, then:

• Enable Testing Cheats
• Select this sim so she is the active sim.
• Enter the following into the cheat box and press enter:
  inventory.purge

Edit... 
I did an experiment with my sim that may be of use...
I had another sim bring a gemstone to their home and leave it in the home. 

Next, I enabled the sims in the home, and to them, as in your video, it tells in options when clicked on that it does not belong to the sim, though I do see additional options since my sim has experience in archaeology and gemology. However, I was able to go into build mode and use the sledgehammer to delete this gemstone:

Thank you I will try the purge , however I do give them items to use later .

i just moved another sim out , and this time I thought  maybe I’ll outsmart the system , and gave her a storage box where she took everything I wanted her to have .

so everything is now locked to this storage box . 
it is happening the same as in the video . I’m opening the storage and the items are stuck .

@Mornimras If you click the storage box in the sim's personal inventory and tell them to place it in the world, are you then able to get the items out? 

Edit:

Which storage chest/box did you use? There is a bug report on a current issue with this here: https://answers.ea.com/t5/Bug-Reports/OPEN-DU-GRO-ICYA-Chest-Keepsake-box-backpack-Inventory-Locked/m-p/10720094#M199444

I can place it from their inventory.

tested it and out the box into household inventory in build mode , and than placed it again , and I could retrieve the items .

firthermore any object that was in sim personal inventory works as supposed to .

thank you for the help !

@Mornimras I'm so happy that worked and thank you for letting me know! Happy simming! 🙌

Thank you for all the help and patience!

I did feel stupid for not trying to place items in the world and than try to "recycle" them trough  household inventory.. you live you learn :D