I recently started using Multibit and today when I opened it the app wouldn't load exchange rates on any of my wallets.
It shows my balance but not the value in dollars. I have it set to do so but it's not working.
Bitstamp is currently offline for security reasons so that will be why. It'll be back within a day or two. Perhaps there's an option to switch it to use a different exchange's rates.. if not, there should be.
Bitstamp is currently offline. Here's how to get prices from somewhere else:
Click on the currency ticker.
This will open the preferences menu.
Scroll down and click the drop down menu labelled "Exchange"
Click "Apply changes"