Can't sell anything in buy mode

So I had to have my computer get compeletly rebooted because it crashed meaning my Sims games got lost. I just re-installed it and playing it realized I can't sell ANYTHING in the game! I click on the 'Sell' button but when I move my mouse away from it whatever object it may be from a computer to a gate is still there. I can place objects fine but the game won't let me delete them! I've read that I have to do something with the cache since the new udpate and I've tried to follow the steps---but I'm at a complete loss as to what to do. HELP!