The good news is: Creator 3.0 should be still installed on your computer. So you just have to put a link to the file on your desktop which has been removed during installation of 3.1 and you can work with it as usual. You'll have to "update" your components to some earlier versions, but that worked easily.
The bad news is: I do not know how to help you further, I would suggest you to create a "MyCase" and tell them your OS-version.
Same thing happened to me, but I just forced the application closed, rebooted and reopened it (the Windows(R) solution) and now it works fine. Go figure.
Wish there was a Linux version, where I might have some control.