One of my oldest couples in Sunset Valley (one of those saves from 2016 to which I returned a couple of months ago) are suddenly acting strangely. They are settled, stable, affluent, both have achieved their life wishes, one now has a wish to be a millionaire ...which will probably be fulfilled soon. Nothing to explain this sudden rash of weirdness.

First, the sim who does most of the gardening now wants to take a circuitous route to the garden, gets stuck (apparently wants to go through a bush rather than walk around it) and stands the waving her arms and screaming about no route. Normally they just go out the back door (kitchen) and they're in the garden; now they go from the kitchen through the dining room, through the hot tub room, through the "lounge" (bar and restroom adjacent to the pool), exit via the side door, turn left and complain of the bush there instead of just walking around it. So I click on the ground near the pool "go here", click a couple of feet to their left "go here", then it's a straight line to the garden (perhaps eight tiles from where they started). There's nothing wrong with the routing in the kitchen, neither sim has any issue when cleaning the house (the trash can is just outside the back door).

Second, the other sim wants to read something, the icon of a particular bookcase appears in the upper left, they go to it, stand there a minute and that icon is replaced by one for a different bookcase, and they go there; repeat for every bookcase in the house til they're back where they started. Continue the entire afternoon, doing laps around the house, bookcase to bookcase. My first thought was they had already read everything in the house, so I replaced about half the bookcases with different ones (I have the "no reread" mod), but that didn't help. So at these times I send that sim to the library; don't have to accompany them, the minute they walk through the front door they want to "read something", and will happily spend the rest of the evening there. (Though they rarely get to finish a book, every sim in town has to come strike up a conversation with them.)

Third, can sims normally climb through windows? Lately when my sims go to the sauna they no longer take the easy way - go through the dining room and you're there. They go out the front door, walk around the front of the house to where the cars are parked (facing the wall outside the sauna), go up to the wall, lean through the window and turn on the faucets, change clothes and step through the window into the tub; when done, they step back through the window into the parking area, change clothes, walk back around to the front door, and come back inside. I put different windows in that room but that had no effect so returned to the originals.

Now, the only thing different ...the only thing new (sorry, ancient song reference)... is that I completed the fence around the lot and put in two gates, locked to all but household. This leaves the front door area and parking area as the only sections of the lot open to the street (it works, recently I heard yelling outside the house, there was some unknown sim waiving his arms and screaming about no route, then ran off down the street).

Old saves got somewhat corrupted over the time and they needs a fresh start.
You can save it as with other name to create entirely new save files with all your proggress over the years, cleaned from cache that has been accumulated. In doubt you can use save cleaning tool to clear out the "garbage" files stored in the old save (remember to do a backup folder).

About the bookshelf you got to replace it with new one, delete the old one and clear the stored books from the family inventory. When selling items from family inventory you gotta sell them all to keep it clean, because when it's full it can make the game to lag more.

Could you provide some screenshots of the fenced area around the house, the gate and the floor plan of the house's ground level?

The routing issues could be because of stuck jigs perhaps? If you use Nraas mods you could try resetting the lot, if that doesn't help then flush any stuck jigs.
https://www.nraas.net/community/post100274#p100274

Be sure to backup your save first (save as a different name) so that you can go back if anything breaks.

Thanks. I've been playing those old (2016) saves for a couple of months now with no major issues (each threw the "some items could not be loaded and were replaced" on first load, but whatever it was must be inconsequential since I noticed nothing changed; in fact the only thing noted was the aquarium was missing from all homes, the mod was inexplicably missing from the packages folder, and searching online did not disclose it, so I used one of the standard aquariums instead). The anomalies noted above just appeared a couple of days ago.

Each active save gets treated with Regul Save Cleaner about once a week.

Will try to get screenshots (if the game cooperates, it has a mind of its own regarding view angles and zoom).

"If you use Nraas mods you could try resetting the lot, if that doesn't help then flush any stuck jigs."

Interesting. Does this affect the game in any way or just clean up things in the background?

The "some items could not be loaded and were replaced" message appears when you have uninstalled or corrupted CC, store, or EP-related items that were removed from the game before opening the save. This happens if they were placed inside the current lot, somewhere around the town, or were sim related CC. That's why the game replaces them with base game items or eliminates them completely.

Edit: For this reason I rarely use custom content in my builds (no matter how many items I have in Mods folder that I barely use) because...well...I could uninstall something important by mistake and regret it afterwards. After that I have to inspect what item is missing or what could I use to replace it.

Reseting the lot (Nraas MasterController) doesn't affect the progress, but resets all current actions, teleports sims to safe place at the front door usually (no matter if they are at home or somewhere else) and refreshes the routing data in the lot.

A "map" of the lot -





and a different view -




Excuse the dark images, game looks fine on my monitor but screenshots always turn out darker (I actually did some fade correction to improve clarity while processing).

Personally I can't see anything wrong with this build.

When placing doors around the house, all exterior door placement arrows must point outside, and you should verify that the main entrance is "set as front door" every time you add a new door leading outside (click on front door > Set as Front Door). The gate's placement arrows must also point toward the outside of the lot; in my opinion, the gate shouldn't be locked right now, because the lock is making the game mistake it for an indoor door.
(The plant which is placed near the launry room door must be deleted or moved somewhere else)

The front door is (was, I'll double check) set as front door, and "points" outward. I fully enclosed the yard and added locked gates to prevent random sims from wandering around the lot (at least they don't help themselves to the pool like the sims on Sunlit Tides); guess I could eliminate the gates entirely, leaving a solid fence, and see what happens.

The sauna is a relatively new addition, that corner of the room originally just had a small table and couple of chairs. I've noticed if my sims merely want to "enjoy refreshing steam" they enter the room normally, it's only when they want the mud bath or revitalizing that they "enter" through the window; it can't be the design of the room, many other sims have a similar sauna room with no issues.

To which room do you refer as the "gym"?

Arrows on objects have always confused me. Does it matter which way a potted plant "points"? Should the coffee table point towards or away from the sofa? Windows are even worse, shutters go to the outside, but that means some windows point in and others point out. I've read exterior doors should point out, but what about interior doors?

Sorry but I got little confused when I've saw the gym equipment in the same room with the washing machine and the dryer, so I called it a gym.

The placement arrows are the triangular cutout inside the placement outlines (the green window under objects when they are selected). Their purpose is to point in which direction the face of the objects is looking at. For exterior doors their direction is important. When the exterior doors arrow points outside it prevents uninvited sims to enter your home (theorically).

The direction of the plants, interior doors or other furniture doesn't matter actually (someone correct me if I'm wrong).

Sims walking thought objects is pretty normal (for me atleast).

In my previous post I was talking about the plant which is in the doorway of the room, where the washing machine and the dryer are. It better to be removed from there, because it blocks the corridor and sims can get stuck there, while doing laundry, or when two sims are trying to exit this room in the same time.

Ah, that plant does appear to be in the doorway, but it isn't, it's just the angle of the image. The residents have no issues there.

But if they are in the kitchen and told to tend the garden, rather than go through the back door to the garden they will go all the way through the house to the side door, stop just outside there and complain of no path, guide them around the shrubbery and table there, and they walk all the way across the back yard to the garden. When done with that work they will return to the house through the back door.