Had the same issue. Here's what happened:
1. In the Illustrator file, I had a image named 'logo.png'
2. I moved the illustrator file to a new folder, along with the 'logo.png' asset
3. Later that day, I had saved A DIFFERENT 'logo.png' to the original location as the first 'logo.png'
4. I deleted the different 'logo.png.
5. Illustrator could open file
Summary - I had duplicated file names, and the newest one happened to be in the same exact folder location as the old one. Make sure you don't
have duplicate file names anywhere else.
HOPE THIS HELPS!