Sharing keynote file as a pdf results in a corrupt file?

I have added graphics to the keynote presentation by copying from Preview.app.

When I share and export as PDF, it crashes acrobat and other pdf viewers on

Windows and Linux.

This is a reproducible error and has happened to a couple of my colleagues recently.

This is a new bug as I have used this workflow many times in the past without problems.

How can I avoid this? Is this a bug?