BootCaT 0.60 will stop working on August 1, 2012.
In order to continue using the program, you need to upgrade to version 0.61 (available on the official BootCaT Website).
Moreover, you will not be able to use your existing Bing AppId: version 0.61 requires a free Windows Azure Marketplace Account Key, see this page for more information.
To find out what version of BootCaT you're running, see this page.