After downloading and running the "Client Tools for Windows" installer from https://hpccsystems.com/download, the following error appears trying to access eclcc:
If the "ECL IDE and Client Tools for Windows" is installed instead (which overwrites the previous Client Tools installation) then eclcc can be accessed normally:
The above test was run on a Windows VM (Parallels on a Mac) as an attempt to reproduce a problem I had see earlier this month. Then, several people with actual Windows laptops experienced similar problems. Therefore, I don't think the VM has anything to do with it.