My model have two error when I click "check for problems in properties and control" error#31 error#131.A massage says"Pressure reference cell for a fluid material is not fluid." How should I solve it?

Thanks for every body's reading this subject, I've just solved them by modify the default values of "monitoring and reference data for air". And I am running it now.Thanks a lot!!

compress the vertex and cell

and properly indicate the pressure reference cell by mouse clicking. I think this will rectify your problem

how to resolve this issue

I do not now what problem it is and how to solve it

The problem is very simple:

You pressure reference cell and monitoring cell for a particular material must lie within that material.

Go to "monitoring and reference" and select appropriate cells.