My office recently started using Keynote for a lot of our presentations. Keynote presentations created on the version that is compatible with Yosemite (and noth

My office recently started using Keynote for a lot of our presentations. Keynote presentations created on the version that is compatible with Yosemite (and nothing prior) cannot be opened on earlier versions. Even if security updates still come for what...usually 20-30 months with Apple...they still don't care about any other kind of backward compatibility and happily break their own file formats at will.