I asked something similar (but not quite) a ways back, but whenever I'm working on large projects that use a lot of hitfilm linking, the both movie studio 12 and 13 will freeze for a bit if I click a different window and then click back onto the program. I've tried everything, using correct file types, running the program as an administrator, turning off gpu acceleration, and setting the program's priority to high with the task manager and nothing changes at all. Anyone else have this problem? It's frustrating because I'll clicked an internet browser to check something and click back onto the program and I have to wait a minute or so while the program freezes. Could it be quicktime?