When you load a movie into a Logic project, the QTKitServer system process scans the folder for movie files that are not supported by QuickTime Player X. This is so that they can be handed off to QuickTime Player 7 to create a Finder preview thumbnail. Normally this only takes a moment, but if a movie file that is not compatible with Quicktime Player X  is incomplete or unusable, then the QTKitServer process may stop responding.

To resolve the issue, move any movie files that are not compatible with Quicktime Player X out of the folder containing the movie you want to use in Logic and restart the computer.