Tiga theme randomly stopped working

One day I looked at my site and realized that the formatting and style for my Tiga theme had completely disappeared–this happened out of the middle of nowhere. I hadn’t even logged in to the admin in a few weeks. What happened, and more importantly, how do I fix it?

I have a couple of other wordpress sites, all hosted on 1and1.com. I tried uploading my edited install and fresh installs of the Tiga theme to both my main site (fatratcentral.com) and my other wordpress sites. It doesn’t work on any of them. Could something on 1and1 have changed? All other themes seem to work fine. Please help!

Thank you in advance!