Small progress
If he fully re-install 2.20.6 (with clear settings), no more slowdown/crash at shutdown.
BUT if he change the "Human" Gdm theme by another, the problem appear.
Small progress
If he fully re-install 2.20.6 (with clear settings), no more slowdown/crash at shutdown.
BUT if he change the "Human" Gdm theme by another, the problem appear.