Excerpt From the WSJT-X website
WSJT-X 2.3 provides a number of features and capabilities that are new since version 2.2. A list can be found in the WSJT-X 2.3 User Guide here. The first several sections at the top of Release Notescontain a list of all important program changes since the GA release of WSJT-X 2.2.
Upgrading from a previous version will be straightforward. There is no need to uninstall or move any files. If you want to make sure to have the latest list of default working frequencies, go to File | Settings | Frequencies, right-click in the Working Frequencies list, and select Reset.
A new release candidate is also available WSJT-X 2.4.0-rc1. For more information and downloads for all versions please visit the WSJT-X website.