When double clicking, the cross platform installer opens the
servoy_installer.jar as an archive file instead of an executable, the extention
.jar is not configured to be opened by Java. Either use the command line option, use the platform's Open with option or configure the platform to open
.jar files using Java.
On OS X, the JRE 8 shipped by Oracle does not have the BundledApp capability needed by the Servoy Developer. The fix is to install the latest JDK 8.