This question came in last week:
Question: I'm using Camtasia Studio 7. I copied my project files to a new laptop. Every time I open a project created on my old system, I get an error message about missing files. I can locate the missing files, so everything ends up ok. But what's up with the messages?
Answer: When you add images and other assets to the Camtasia Clip Bin, the path used in Camtasia does not update should you change systems. Since the path name to those assets is different on each system you use if you import from, let's say, My Documents, Camtasia can't resolve the path. To avoid these kinds of error messages, I always work on my projects directly from my C drive (C:\). When I move the projects from system to system, I never get those messages (assuming I drop the project files at the root of the hard drive on each system).