When I try to run the codes from tutorial:FreeSurfer MRI reconstruction — MNE 0.23.0 documentation, I got an error: RuntimeError: Render window interactor must be initialized before processing events. Does anyone know what I missed in this process? THX so much!
Hello @takitzou and welcome to the forum! I’m tagging @GuillaumeFavelier here, who might know more about this! 
@takitzou if I’m not mistaken you wrote on discord too
If that’s the case, I know that you changed your version of vtk to 9.0.0 but for some reason, I see on your log that the mayavi 3d backend is still used which makes me think that there could be a missing dependency preventing the pyvista 3d backend to be loaded correctly.
Do you have pyvistaqt installed and up-to-date as well?
Can you confirm that the following snippet (unrelated to mne) opens a window and displays a cone?
import pyvista
from pyvistaqt import BackgroundPlotter
plotter = BackgroundPlotter()
plotter.add_mesh(pyvista.Cone())