picture disappears but keyframes and scenes and panels are there

I have to do a project at home and at school. I worked on the project at home and uploaded the file to google drive so I can work on it at school. I downloaded the file from google drive on the school computer. When I import the file on Storyboard Pro the thumbnails and layers are white. The key frames, scenes, and layers are all there, but they are white. Please explain. Thanks