Timeline Red and Yellow, Rendering and Exporting Not Working

As the title suggests, I cannot export or render my project. This is the second time this has happened, and it seems to come out of nowhere. The project I’m working on is only 8 seconds long, which makes this even more frustrating.

When I try to export or render, the small loading tab pops up but doesn’t move. It stays at 0%, and there’s no estimated completion time either. I also can’t play back the video I’ve made—I can only hear the audio, and not even all of it. For some reason, my main music track has been cut out.

I’ve been trying to fix this for hours, but nothing seems to work. I’d really appreciate any help!