I bought a new fridge for my sims, put it in the same place as the old one, but no one in the household could get to it. They got the thought bubble with the crossed out footprints. So, I re-purchased the old fridge and put it back in the same place but still, they can't get to it. I have tried moving everything in the kitchen even though there is no possible way that anything is in the way. Still, the fridge is off limits. I even tried changing the flooring! Resetsim doesn't work either. I need help! The Grim Reaper is planning a visit.
Exactly the same thing happened to me and my two sims when I started playing in Isla Paradiso. They simply couldn't use the fridge, and there was a large area in the kitchen that didn't work normally. I couldn't put anything there and it was impossible to delete the foundation with the hammer tool.
I think it could be a new bug that came with Island Paradise expansion, because I don't remember ever having encountered it before.
Anyway, I solved the problem by going to Edit town, evict the family without the house, copy house to bin, bulldoze the house, place the copy at the same lot, put the family back and return to game.
I've had those strange grey ovals turn up here and there in my game too, and I've been able to delete them with the cheat Move Objects On.