image doesn't show on the stage when i drag it from the library

While I was rotoscoping this image on my desktop last night my computer "blinked" and everything just went gray.  All of the images that I had loaded on the stage to trace just vanished, but the bounding boxes that the images were contained in are still present, but the images are gone.  This morning, I restarted my computer, but I'm still not able to drag any images from the library onto my stage and I have the same issue on my laptop.