Freeship design hidrostatics floating point division by zero

I got a "floating point division by zero" error when trying to run design hydrostatics in Freeship 3.30+ on the attached model. I have tried several things to get rid of the error (restarting, exporting the model as part and loading it, moving it around, changing project parameters), but the problem prevails.

What could cause this, and how to get rid of the error?

Update: If I make the lines at x=0 creased, design hydrostatic works. If I uncrease them again it is not.

 

seems to work with 3.40 whether creased or uncreased, so maybe try a different version.