Arved Wintzer

That would also be an option. I implemented the warning here, it works well: https://github.com/arvedes/openfoam-adapter

My simulations worked well with this fix. What error message do you get? Did you try to run without coupling?

Dear Habib, Good to hear that you resolved the OpenFOAM issue. Unfortunately, I don't have any experience with deal.II myself, so I may not be able to offer much assistance....

I'm not sure if that really belongs here, but it seems somewhat related: Would it be possible to define a coupling boundary from an external mesh, as it is done...