War at Sea wont load

I am using Vassal 3.1.16. However the WAS vmod will not load. I get a warning that this file cannot be loaded.
However Victory in the Pacific loads on my MAC
Do I need an earlier version?

bos

Can you confirm that you are using this procedure: File menu → Open module → choose War at Sea module?

Do not use the “Import module” menu item–this is for converting modules from the ADC2 software.

Sounds more like you are trying to load a zipped module not a mod file.