Transitions, Photos, Music, Text buttons do not function. How to fix/troubleshoot the issue?

I'm trying to perform edits onto one of my videos and trying to insert text, transitions, and music. Unfortunately, the buttons to open those menus do not function any more. They only grey out like they would normally when clicked and that is it. Thus far I've tried to close and re-open the app, and I have not had any luck searching online for a solution (maybe I was looking in the wrong places or wrong ways?). Anyone else run into this situation or have a solution/troubleshooting help?

Thanks.