Paste function greyed out when exporting iMovie clips

I am trying to take a ling video and split it up into several individual files in iMovie. I watched a few videos and read several posts about how to do this. they all say the same thing but it is not working for me. It says to split the video into clops, copy a clip, start a new iMovie project, and then paste the clip into a new project. However, when I try to paste the clip into the new project the paste function is greyed out so it won't let mer paste the clip into there new project.

What am I doing wrong?

[Re-Titled by Moderator]