I have small issues with ArcGIS Earth v1.4 build 1586. When I rename the root node "My Data" in the layer list, it works fine and I can see the change in the json file, but when I reload the workspace next time the change is gone and the root node is back to "My Data".
Also, when I tick / untick some nodes before saving the workspace, I also can see the changes in the json file (isVisible=true / false") but at next reloading it does not recall my choices and everything is ticked back again.
Regards,
Serge