Apple will be releasing macOS 10.15 Catalina fall 2019. Apple has made the decision to drop all 32-bit application support with this release, which will impact EndNote.
EndNote X9 for macOS will be extensively updated for compatibility prior to the launch of Catalina. If you already have EndNote X9, please install all updates as they become available to avoid interruption in your workflow.
EndNote X8 and earlier for macOS Users
Since Apple has made the decision to drop all 32-bit application support, we expect that macOS 10.15 Catalina will not run EndNote X8 and earlier. However, we want to continue to support you. We recommend one of two options:
Please visit https://support.clarivate.com/Endnote/s/article/EndNote-for-Mac-macOS-Catalina-Compatibility?language=en_US for more information.
EndNote Library Basics
Adding References
Cite While You Write
Styles Menu in EndNote on a Mac
Find Duplicates Dialog Box on a Mac
Format Bibliography Dialog Box