Cannot Render project

Hi
New encore user here so I really hope this is just a stupid question.
I've gone through the poster frame process for my main menu 'play' button but the clip I chose to play is not playing when I preview.
When I go to file/render - none of the options (ie. project, motion menus, slideshows) are selectable. They're just faded and will not highlight.

Any ideas please?