Google Earth 126.96.36.1991 was the last version that supported the Leap Motion Controller and last year Google announced that support for earlier versions of Google Earth has also been ended, you can find the announcement here.
We would love to see our hand tracking return to Google Earth and I would recommend making your voice known on their online community if you would like to see this appear in future versions of Google Earth as well!
If you are accessing applications via the Leap Motion App Store/App Home then unfortunately this will be why you are having issues trying to get these to work correctly. We retired the App store on June 30th 2017 and these apps are now available via the Leap Motion Gallery which is available here.
We also have some FAQs about this here which might help with any questions that you have about this retirement.