If you look at the list of installed components, it should give you the ability to click or right click on the definition that did not install properly and you should be able to get more information on what happened. Also, you may run into problems if you are just getting the definitions and not the program updates that go along with them. There is a system in live update that assigns prerequisites for downloading and installing certain components to guarantee that what you do have will work and not trash your system, but it isn't totally infallible. I would also suggest just rebooting your machine and trying again.