Gmsh import error

[dokken]

Please search the on the forum for your error message before posting a new question.
If you search for

Unknown value “mixed”.

The follow thread comes up.

Transitioning from mesh.xml to mesh.xdmf, from dolfin-convert to meshio

First, you need to use physical markers on your lines and surfaces See for instance this tutorial: https://jsdokken.com/converted_files/tutorial_pygmsh.html In particular have a look at part 3. What you should also do is inspect the objects that you are trying to access. I.e. print msh.cells[“line”] etc.