Keynote 6.6 / El Capitan

[Beliblis]

I've noticed that any Keynote presentation created or modified by Keynote 6.6 will NOT open in 6.5.3 or any earlier "6" version of the software. Unless, of course, you export it in Keynote 09 format.
So they've "improved" Powerpoint import/export, and in return ruined compatibility with their own software. Thanks for that, Apple

Luckily, I kept my old Keynote version. But every time I open Keynote 6.5.3, it prompts me that "there's a new version" of the software.

Does anybody know how I can get rid of that? (Maybe via LittleSnitch or HandsOff?)

 

[Ebenezum]

I am fairly certain Little Snitch will be able to block that prompt.

I agree, Apple has very poor record when it comes to backwards compatibility. I got fed up with new "improved" iWork software and I am using iWork 09 into foreseeable future...