@pim_artittaya Sorry for the delay, but this issue is even more persistent and irritating than I thought. I did manage to fix the Van Gould build (Midnight Hollow), sort of, but it required removing a lot of objects you might not want to disappear. And it's clear that a number of objects are involved. For example, removing these objects prevented any flashing on the second floor (with the bedrooms):
- all windows
- all fireplace items
- the four outdoor lights around the backyard pool
- the French doors and Mags' doors
- all wall mirrors and the Empress Vanity
The doors only caused problems on the second floor when in build mode, or if I put the walls up in live mode; cutaway was fine.
These additional items needed to be removed for the third floor to stop flashing in all scenarios:
- all doors
- the five pool fountains
- the standing mirror on the second floor
- Bathroom Junk Holder, Finders Keepers Hutch, Granddaddy Clock, and Immoderate Water Fountain
I'm not totally sure that all objects are implicated, in particular the last four; I just deleted anything that looked like it might have a reflection. I'm sure that at least some of those objects cause flashing though, and I also needed to remove at least one item in every bullet point to get rid of the problem. Similarly, I don't know for sure that all windows are a problem, but not removing them meant lots of flashing on the second and third floors.
It's also possible that some of these items only cause flashing when paired with other items, for example, perhaps the windows are fine unless the lot has a pool. I haven't gotten that far, and to be honest, after 3.5 hours of testing, I was ready to take a break. But you could experiment yourself if you wanted; it would help to know what you found.
Finally, I ran the game on minimum settings and saw zero flashing. However, most of the lots were partly colored red in Map View, not something you'd want to see, and of course the game looked awful. When I go back to testing, I'm going to try to find out if there's some combination of settings where neither problem is present.
In the interim, I'd just suggest playing different lots and/or keeping the camera zoomed in enough that you don't see any flashing. The flashing isn't harmful to your computer, just extremely annoying.
Edit: I forgot to add, I mostly used NRaas MasterController to flush the objects. It shouldn't make a difference in general, but it's worth mentioning because I could never find the second water fountain looking on my own, but MC insisted it was there.
