Exporting a Rhino file to Wamit.gdf

Hey, when exporting a Rhino file to Wamit.gdf format the following warning signal appears:

“Failed to saves as U:/…
The file writing plug-in failed”

Even when I try and create a basic mesh in rhino and try to export, this warning sign appears

I was wondering what were the recommended basic steps for creating a mesh in order to export to a WAMIT gdf file?? –

Any help will be much appreciated, as I am super new to Rhino
Many thanks

What if you try saving to a local disk (e.g. c:)?

– Dale