If you receive a message to update to X9.3.1. Follow the prompts to download and install from the webpage.
If you have X9.2 installed and check for updates it will tell you that EndNote is already up to date. It will may not show the update to X9.3.1.
Follow this link for instructions to manually download and install the patch.
Remember to check your library is located in a 'safe' folder location: https://www.crandon.com.au/endnote/faq/Win_folders.html
After updating to X9.3.1, you will need to convert your library to the new 64bit format. EndNote will make a converted copy.
The original will remain incase you need to use it with older versions of EndNote.
You can use sync to move your data to a different system with older versions.
Click Yes to continue.
In the Save As: dialogue, EndNote suggests the original library name and adds the suffix "-Converted"
You can change the name to anything but make it obvious this is the new version, use a meaningful name for your libary like MasterLibrary-Converted, try to stay away from MyEndNoteLibrary the default name used by EndNote.
If you are syncing your library to EndNote Online, save the converted library in the same location. Back-up and sync.
You will be warned that this is a different library. Click OK and sync. No changes should be made.
If you want to share or move / copy your library to a machine with a previous version of EndNote, you will need to either share the library with EndNote Online or Sync to your own machine. The newformat is NOT compatible with older versions.
Some users only see the EndNote Online tab in Word after updating to EndNote or updating Word.
This link: Word add-in changed to Online