I’ve had this save for a little while, and I’ve wanted to not only makeover the WA worlds, but also add places like Riverview and Bridgeport as Traveler worlds. As silly as it might sound, it’s felt overwhelming, but I finally decided to start working on making over the WA worlds, and something possibly very weird has happened….
I haven’t traveled much, so hopefully I did at least this part right: I had my sim make the “Travel” call on his phone and right-clicked him so I’d be going “alone”. I’ve started working on Shang Simla, and have downloaded a few things to hopefully jazz up the place (I had forgotten how much “nothing” there is for non-adventurers to do!!). So far, all I’ve uploaded to my game folders are a couple souvenir objects (which I put into sub-folders of Mods/Packages) and some Chinese sims (who I put in SavedSims). I haven’t placed the objects in Shang Simla, and I haven’t put the downloaded sims in my game – IIRC I haven’t even looked at them in CAS yet.
So, yesterday my game crashed three times (I’m not sure how much to worry about this), but here’s the weird part. When I went to clean out my CurrentGame.sims 3 folder, in addition to the usual files, each time there were 18 .sim files of some of my newly-downloaded sims! And each time, they were the same files.
I’ve only been playing Sims 3 off and on for a few years now, but I don’t remember ever seeing this happening. Does anyone have any thoughts or suggestions?
(It’s possible I’m not phrasing this very clearly, and if so, I’m sorry… I’m on a lack of sleep, but I really would like to get this mystery solved, if possible.)
Thanks so much for your time!

I've never seen .sim files in the CurrentGame folder. Are you certain you didn't accidentally copy them to the wrong folder? The crashing is probably nothing to worry about unless it becomes more common. When you're doing heavy things like build/buy/cas the game will run out of memory and crash often.

*facepalm* Yeah, I bet I did that, moving files around and not paying close enough attention. So far, the game hasn't crashed again, but after taking the .sim files out of the world's folder, I haven't seen them there. It's embarrassing, but I didn't know that build and buy were as heavy as CAS, so, hey, I'm glad to learn something new! Thanks very much!