EDIT: On October 9 Quark released the El Capitan Update for QuarkXPress 2015, so this article is obsolete. Please read this instead: http://www.planetquark.com/2015/10/09/quarkxpress2015-on-el-capitan/
On Sep 30, 2015, Apple released OS X El Capitan, also know as OS X 10.11.
Unfortunately as El Capitan handles some mouse movements differently than OS X versions before, QuarkXPress 10 and the current version of QuarkXPress 2015 crash once you move the mouse cursor over a palette.
So please do not use QuarkXPress on El Capitan for production yet.
Quark has a compatible version of QuarkXPress 2015 in pre-release tests which is ready to be released in October.
However as the release version of OS X El Capitan is a slightly newer version than the Golden Master Candidate, which Apple distributed several weeks ago, Quark is currently rechecking this new update of QuarkXPress 2015 with the release version of El Capitan.
If there are no surprises, Quark will release a QuarkXPress 2015 Update compatible to El Capitan within the next three weeks, so before October 22, 2015. That’s also the same time frame that it took Quark the past three years to make QuarkXPress officially support the newest version of OS X, so it looks like also this year it’ll stay within this time-frame.
Quark will inform you all once the El Capitan Update to QuarkXPress 2015 has been released. And of course this is a free update for QuarkXPress 2015.
And Quark will NOT support using versions before QuarkXPress 2015 on El Capitan. We do know of a crash bug of QuarkXPress 10 on El Capitan that we are currently looking into fixing. However, we will not support QuarkXPress 10 on El Capitan.