Installing or Reinstalling XQuartz if Upgrade to macOS 10.15 Catalina Causes Issues 12.14.2020 Anonym If you had XQuartz previously installed before upgrading to macOS 10.15 (Catalina), or you have not yet installed XQuartz, follow these steps to get IDL 8.7.3 or ENVI 5.5.3 running on Catalina.