EndNote users should be aware that versions X5 and earlier are not compatible with Mavericks update to OS X for Macintosh.

Thomson Reuters are currently testing new and historic versions of EndNote on this operating system and have confirmed that whilst no EndNote releases are officially compatible with Mavericks, versions X6 and X7 seem to operate as they should based on preliminary testing.

Versions X5 and earlier do not seem to fare so well in Mavericks and unfortunately do not seem to be able to launch at all. Any users still using EndNote X5 or earlier are advised not to upgrade their operating system to Mavericks, as this may render their reference libraries inaccessible. Any users of EndNote X5 or earlier that would still like to use Mavericks are recommended to upgrade to EndNote X7 in order to ensure compatibility.

The following link will take you to a Knowledge Base article by Thomson Reuters where general compatibility information on Macintosh operating systems is stored. As Mavericks was only released on Sunday 27 October there is no information on it in the article yet, however as and when new compatibility information is available regarding OS X 10.9, it will be available on the Thomson Reuters Knowledgebase.

Update 19 November 2013
If you are using X7 it works with Mavericks however for official Mavericks compatibility plus several bug fixes and sync improvements the EndNote X7.0.1 Mac update has been released. This is available via Help > EndNote Program Updates or go to EndNote available updates to download and unzip the update.

For further information contact your librarian.