Hi Carlos,
I just encountered same issue and found your trick works well for me! Thanks!
After a little bit more searching, I found
HTML(X3DOM.html(mesh))
works too. This can be refered to 3D plotting with X3DOM in docker container
I’m not a python expert, but I’m wandering if this is related to which data type that X3DOM refered to in the fenics 2018.1.0, looks similar to the renaming of mpi_comm_world() to MPI.comm_world.
Yang