Same notebook and same problem here. It happens with both Ubuntu Gnome and Ubuntu Unity. Haven't tested flavours.
I thought it might be the GPU driver but all of them do the same thing.
I also tested booting into kernel 4.2 but also doesn't work.
I thought it might then be Gnome 3.18 but Fedora 23 works.
This happened in both the beta and the release of Ubuntu.
Same notebook and same problem here. It happens with both Ubuntu Gnome and Ubuntu Unity. Haven't tested flavours.
I thought it might be the GPU driver but all of them do the same thing.
I also tested booting into kernel 4.2 but also doesn't work.
I thought it might then be Gnome 3.18 but Fedora 23 works.
This happened in both the beta and the release of Ubuntu.