The Image Optimizer plug-in in the PDF Import package optimizes the memory used by files that are linked more than once. This hotfix solves an issue with images, placed more than once inside plug-in art objects, being lost when opening the .AI file.
This problem affects the dynamic images maintained by Dynamic Content and also for example, native Adobe® Illustrator® Live Trace images.
As a workaround, remove the PDF Import package or the Image Optimizer plug-in in the package.
After creating a file with dynamic images in Dynamic Content, the file is saved and closed. But when the file is re-opened, the images are not visible.