[Barry Martinson]

Try to place the files in a blank AI CS document instead of opening them.
But you have to choose show all documents from the place dialog window in order to be able to select the AI file you want to place.

Also trash the AI CS preferences before attempting this!
If you are still experiencing the issue after applying this fix you can try Illustrator Fix Toolbox
https://www.fixtoolbox.com/illustratorfix.html