Today, while I was editing a video on WMM, I wanted to cut a clip in half. Instead of pressing M, I accidentally pressed N. After I pressed it, it looked like WMM had frozen, but then some of the clips on the timeline looked grey with an arrow on the side. And when I hovered my mouse cursor on top of some other clips, they disappeared. I saved the project and opened it again, since that usually fixes the problems (for me at least). But when I opened it, this is what it looked like:

On the timeline, it looks like no clips or audio have been put in, but it still shows that the project is 4 minutes long and it shows ''Item 1 of 32'' in the bottom left corner (Also the Video Tools and the Music Tools at the top). 

When I try to play the project, there is no video or audio. Also, when I close Movie Maker, re-open it, and then open the project, this is what it looks like: