Did you download Google Earth Pro when it became free, a while back now, but haven’t updated it since? The latest Google Earth Pro 7.3.1 update brings “new 64-bit support, performance improvements”. There’s no auto-update in the software, it seems, so you have to go fetch the new installer manually.
Possibly of interest to readers who use Google Earth to find terrains that can then be extracted from datasets for use with 3D landscape software such as Vue and Terragen. Or those who donate 3D building models to Google Earth.