Jan 24, 2018:
Google Earth Pro 7.3.1 has just been released:
For the first time in 14 years a 64-bit build has been introduced, to which Google Earth Pro automatically updates.
Unfortunately, this 64-bit version does not include the COM components required for Plex.Earth and other applications to communicate with it.
To solve this issue we recommend that you uninstall the default 64-bit build and replace it with its its 32-bit counterpart which offers the exact same capabilities while also being fully supported by Plex.Earth.
You can download the 32-bit version from the link below:
To check which version is currently installed you can go to Google Earth's "Help" -> "About":