My sims have no problems with public pools, nor with ones I build on their lots. But on two worlds my sim has been invited to a pool party only to be incapable of entering the pool. I click on the pool, select "swim", they change into a swim suit, walk to the edge of the pool, stomp their foot and complain of no path. Click on the ladder and tell them to use that, same result. Other sims are using the pools with no problem.

I spent an evening searching for a solution; no luck, most answers didn't seem pertinent - yes, I was invited (not trespassing), I talked with the host(ess), mingled with guests, pool is functional for all NPCs, and it is a default pool (not one I built).

One is the Wolfe estate in Sunlit Tides, there are two pools there, one in front and one beside the house. I've been invited to pool parties there twice, never able to swim in either pool, though everyone else was having a good time. (For revenge I stole his wife, she now lives with me, lol.)

Base game with Ambitions, Seasons, and Generations; minimal CC at the moment, some clothing, cars, and NRAAS mods.
Win11 (yuck), i7, 16gig RAM, GTX1070.

I will have to test those specific pools in Sunlit Tides. Has been a while, since I played on that map.
I am just about to start a test for another user's issue, so I will combine it with yours and let you know, if those pools work for me.

You sure about the map?
A "Wolfe" household doesn't exist on Sunlit Tides, so I cannot really find the house in question you are talking about.
Maybe you mixed it up with the "Wolff" household from Pleasantview/Sunset Valley (The "stolen" wife would be Morgana then)?

Ah! my apologies; at least I'm old enough to blame this on a "senior moment", lol (both towns having "Sun" in the name). The other pool was at the Landgraab estate, but don't recall offhand which town that is in (the house is at the end of a dead end street, pool is narrow rectangle behind the house).

Currently installed worlds are Sunlit Tides, Sunset Valley, Twinbrook, and Hidden Springs.

(And yes, Morgana is the lady in question, though her moving in with me is entirely coincidental to the pool issue ...but it makes a good story.)

Alrighty, so their pools at their villa at the dead end on that cliff are the issue, where I can reproduce the problem, yes?
I faintly remember having been there in some play-through to pool parties without issues, but I will try.

Will try to get a screenshot to make sure we're looking at the right pool for Landgraab (have eight active sims on four different worlds, not counting households with two sims in same save).