Moving this discussion to the InDesign forum.
InDesign 8.0.2 is InDesign CS6. InDesign 9.x is InDesign CC, which is a whole 'nother version. If your Help -> About says 8.0.2 then you are not using InDesign CC.
version 8.x is CS6... download the CS6 CC exchange app.
wait a min: thats something else
they would have to save as IDML