Draw() display nothing

[Thomas-GT40]

Hi, I'm Trying to do one of your tutorial, (3D solid Mechanics - https://docu.ngsolve.org/nightly/i-tutorials/wta/elasticity3D.html), but i don't succeed to display anything. The code run ok, no errors, but it don't display anything. I check jupyter, and it look like to be good. Do you have any Idea what it can be ? Thanks