You have a new computer. If it's a mac, the 2010 version may no longer work correctly as mac os upgrades are not nice to old software.
I assume you are downloading the 2010 version from the "previous versions area" of moneydance. If you state which OS you are using (Windows/Mac/Linux), then I'm sure someone will examine the file, but I'd suggest you also try again, if there was a download glitch. You can speak with more authority if you try more than once.