I've been working on three separate videos. Today I opened one of my projects but the folder no longer shows up in my media. The project folder is located in my pictures folder, but when I open the pictures folder in Edit Pro, everything shows up except the project folder.
I'm assuming the project folder does actually show up in File Explorer in the location where you believe it should be? If not, use Start > Search > For Files or Folders...to locate it.
I wouldn't personally keep it within 'My Pictures'.
Wherever you've chosen to put it, the Projects folder location should be set in MEP as shown here, in the Program Settings window:
If you need further help, provide more detailed information. See the prominent request at the top of the forum page: "PLEASE DO THE FOLLOWING BEFORE POSTING YOUR QUESTION".