Stealing the sims 4

@lietjesims  Do you have any Mods that have a setting on them that would be related to this action? If so, you could try adjusting the settings.

Following are some initial things to begin troubleshooting. If these do not help, we can advance to other possibilities.

Again, do you have Mods or CC (or have you ever had them)? If you do please remove them in this process and try the troubleshooting as described below. (If you don't have Mods or CC, just skip the part about removing the Mods folder, but still delete the cache file mentioned and run the repair.) If you ever had Mods or CC in the past then do the steps as if you have them currently (removing the Mods folder), as there could be damage that has remained after you removed them.

• Exit your game then exit Origin. Please drag the Mods folder from your 'The Sims 4' folder onto your desktop (for future reference) then delete the localthumbcache.package file in your 'The Sims 4' folder. (When you restart the game it will automatically create a new Mods folder.)
• Next please run a game repair [ Open Origin, click 'Game Library' then right-click Sims 4 > Repair Game ]. Make sure to let it run until it has completed all repairs (it will do the base-game first, then run through each of your expansions/packs). After that, please see if the issue has stopped.

If it was Mods/CC: If this fixes the issue I would recommend that you check with the Mod and CC creators to see if there are any known issues with their Mod/CC clashing with the recent update and if so do they have an updated Mod/CC that will address the changes in the game's code from the update. You can then re-add your updated Mods/CC one at a time to see if one was conflicting with the function/causing the glitch - but do not re-add the old Resource.cfg file from the old mods folder, as it’s possible for it to have become corrupted.

If you have a lot of Mods or CC you can do so by via the 50/50 method. Let me know if you need directions on this.

@lietjesims, in addition to what @SheriGR suggested , if you have the Eco Lifestyle EP is could be caused by one of the N.A.P.'s being voted into action.  There is one called Sharing is Caring that causes other Sims to be able to steal your stuff or other's stuff. 🤨So, if you have the Eco Lifestyle EP, just keep that in mind! 😉

@PugLove888 Whaaaaatttt??? I had no idea about that one! That's crazy! Wow! Thanks for adding that!

@SheriGRwell, I know you like to test all the build options first, each time we get a new pack! 😇 Nobody can be aware of everything! 

@PugLove888 Yes, I've been building, and only playing brief situations for AHQ tests. Sounds like I'll be adding locked doors and fencing... and seeing what I can disable. That's definitely not my play style. I have easy-going, nice sims. But... I've had them pick a fight and beat the tar out of a sim in two conditions... a vampire who would not leave them alone and was coming in the house... and a NCP stealing and refusing to leave their property.

@Trismagistos, I have mostly tried out the Maxis-made households and built some of my own, and of course did some testing to answer questions here. But that hasn't given me a lot of time to play enough to see most of the NAPs.  I've only seen 3 so far.  The Roughhousing one, the exercise one, and the cooking one.  But these were all in separate Save Game files, as I don't usually play rotationally.  That could also be a factor. 🤔

So far I have enjoyed what I've played, but I still have a lot to discover! 😉

@Trismagistos Unfortunately, I heard Sims randomly kiss others with that 'Free Love' NAP. This would upset me, as all of my Sims are very monogamous!!

@PugLove888As soon as Eco Lifestyle got out I returned to my favorite Sims to test out all the new traits and skills. I just finished his fabrication skills and he is now working on his juicing skills

I agree that there is still a lot to discover. Some tricky paint stuff for example... 😉