I'm really confused now.
I've upgraded to 17.10. On my login screen I choose "GNOME on X.org" and NOT "Ubuntu".
I too see the option in tweak tool to disable ubuntu dock, but toggling the switch has no effect.
So the answer "Install gnome-session" for a vanilla gnome doesn't seem to actually work. (At least not for some upgrade paths).
So, like Joseph Jasson wrote, one way or another there is a bug. Either in the tweak tool or in the extension itself.
I'm really confused now.
I've upgraded to 17.10. On my login screen I choose "GNOME on X.org" and NOT "Ubuntu".
I too see the option in tweak tool to disable ubuntu dock, but toggling the switch has no effect.
So the answer "Install gnome-session" for a vanilla gnome doesn't seem to actually work. (At least not for some upgrade paths).
So, like Joseph Jasson wrote, one way or another there is a bug. Either in the tweak tool or in the extension itself.