The current version is 7.1.1 (released on December 22 2021).
Important: After the newest Windows updates ChemProp may not start anymore. To fix this, there is a solution available for download. The newest fix has been provided Nov 14 2022.
Be aware, versions prior to 6.7.1 are expired already, and 6.7.1 only works together with an installation of 7.x!
The change log is located here: