Apparently, you can't make clips clips "unique" in the FL Studio Demo Version. I tried to make a clip "unique," and a window popped up and said that this wasn't allowed in the demo version. When I clicked "okay," everything in my playlist disappeared. I could still paint in clips, but I wasn't able to edit anything. It was a good thing that I could still render my project. The step-sequencer still works, because I used FL Studio's drum loops as a reference for my remix of a Ramses B track. As you can tell, I didn't get very into the track when the bug hid my clips. I really like FL Studio, so I'm hoping to get the full version soon. Comment if anyone has a solution/reason for this happening.