Bulldoze lot not working, freezing

I wanted to replace a lot that I downloaded from the gallery as I no longer wanted it there in Evergreen Harbor. I go to build mode, clicked on bulldoze lot, I see a brief message saying "Invalid Object" and I see the spinning circle and it won't stop. I can't even go to the pause menu to save the game. I'm in dire need of some help as I do not want to quit the game on fear of corrupting the file.