Epic Games (maker of Unreal Engine and Fortnite) has acquired Quixel. Quixel Suite is now discontinued and no longer supported. Moving forward Mixer 2020 is the replacement for Quixel Suite and will be available to everyone for free.
You can still download the unsupported version for free at http://quixel.se/download/.
For our academic customers, you may also want to consider some of the benefits of Epic Games Unreal Engine for Education.
For more information on Epic Games acquisition of Quixel checkout https://quixel.com/blog/2019/11/12/quixel-joins-forces-with-epic-games.