I have found that sometimes if LeanFT was installed by a user that does not have proper permissions, and often if UAC is set higher than ''Never Notify'', you can get this error message too.
Uninstall LeanFT, ensure you have proper rights, lower UAC level, then install again and it should work.
LeanFT permissions are detailed at: http://leanft-help.saas.hpe.com/en/12.53/HelpCenter/Content/Installation/LeanFTInstallation.htm?Highlight=install#Required. Even though this page says ''You can install LeanFT with User Account Control (UAC) turned on or off.'' I have found that group policies and user admin levels may affect it. I recommend turning UAC off for the installation the turn it back on once complete.