EndNote libraries are made up of two parts: the .enl file and the .data folder. These two parts must be kept together. Both are needed for the library to work correctly.
EndNote libraries should be kept on your computer's hard drive. Storing and editing libraries on a network drive can lead to corruption and performance issues.
Do not store your EndNote library in cloud-syncing services such as DropBox, OneDrive, etc. Cloud-syncing folders corrupt EndNote libraries over time.
Uninstall your previous version of EndNote before installing a new version.
Considering switching EndNote versions? See the "What's new in EndNote 20" video before making changes.
EndNote trainers have also observed these changes.
EndNote for Mac
Settings for the Find Full Text function
Please note: EndNote cannot always find the full-text. Be sure to double-check our databases or print collection. You can use drag-and-drop to attach full text.
Doing a systematic analysis? See this article from the Journal of the Medical Library Association: "De-duplication of database search results for systematic reviews in EndNote."