Since yesterday, all the bells I click on will say treasure expired. I'm wondering if it has something to do with the Google Chrome extension that finds bells for you. Thanks for your help!

That extension defeats the purpose of the Treasure Hunt, because you are not hunting for them. I would delete that ACC Bell Finder extension right away. Also, there was a topic like this a while ago. It has everything to do with the bell finder. Next time you find bells, refresh the page and then see if it adds to your bell count.

Please see this thread. I'll lock this one, because we don't want to hash it all out again.