How to solve foer error code?

Hi @soahn1, thanks for posting

Since we don’t have access to your project, we can’t know for sure what the issue is. However, for fluid flow simulations you need a driving force for the velocity, and everything coming in needs to come out. That’s why the most usual combination of boundary conditions is Velocity inlet + Pressure outlet.

You can take the cases in our tutorials page as examples:

Cheers
Igor