Here's my problem. I'm creating a "retirement" community and am using the big, central park lot from Sunset Valley (changed lot designation to Residential). As I began to build on the open area opposite the public toilets, part of my foundation wouldn't take and a message popped up saying that other objects were already there. Of course, these objects were hidden, otherwise I would have moved or removed them before building! I suspect that the objects in question are the picnic basket/blanket that appears when sims are in the park. How do I locate or make these objects visible so that I can either move or remove them?

I had the exact same problem when building on Sunset Valley's central park. What shape are the patches that you can't locate? Large and round like the one in this picture?

If you both have Seasons, then this could be due to seasonal items on the lot. Turn on buydebug, see if there is a silver ball (seasonal marker). If so, shift click on it to change the season setting, and you should see the seasonal items.

Otherwise, it may be spawners or spawned objects causing the problem- in which case buydebug will reveal those, too.

You should also create a small basement so that you can check underground for spawners, since the lot did have a lake on it. Sometimes they get trapped underground.

It wasn't the spawners in my game; I cleared them all out and bulldozed the lot. There were no silver balls, either, even with BuyDebug on. One of my problems were SocialJigs. Deleting them through MasterController helped. However, I did still have to make a backup copy of their house and occasionally bulldoze the lot and replace the house.

Thanks for the guidance, one and all! Since I don't use BuyDebug cheat very often, I forgot to try it first! As I suspected, the object that was primarily blocking my foundation was the Public Picnic Spot, which I subsequently moved. BuyDebug also uncovered a butterfly spawner and a seed spawner in the area where my building would be, so I moved them also. However, there remains a white cube that cannot be picked up and moved (see screenshot). I'm not sure what it does, but hope it won't interfere with my building. As you can see in the screenshot, it does fall outside of the building, so I'm assuming that it won't interfere. If anyone can identify it and let me know if it will cause a problem, I would sure appreciate the feedback! Thanks again for your assistance.

I believe that white box represents something that's already spawned, so even if you delete the spawner, the spawned object/thing will remain there until collected by a sim. It shouldn't impede your building in any way.

Thanks, eskie227! That makes sense, as the cube was initially directly adjacent to the butterfly spawner. Guess I know where to look for butterflies once I complete the lot!

Or, with testingcheatsenabled true you could shift click on the item to delete it.