Hardware Enablement Stack (HWE) out of support

I had the same problem, this is what worked for me

Command:

For amd64:

sudo apt-get install -V libglapi-mesa-lts-trusty libgl1-mesa-glx-lts-trusty xserver-xorg-lts-trusty xserver-xorg-input-all-lts-trusty xserver-xorg-video-all-lts-trusty libgl1-mesa-dri-lts-trusty x11-xserver-utils-lts-trusty libglapi-mesa-lts-trusty:i386 libgl1-mesa-dri-lts-trusty:i386 libgl1-mesa-glx-lts-trusty:i386 libgles2-mesa-lts-trusty libglapi-mesa-lts-trusty mesa-vdpau-drivers-lts-trusty

For i386:

sudo apt-get install -V libglapi-mesa-lts-trusty libgl1-mesa-glx-lts-trusty xserver-xorg-lts-trusty xserver-xorg-input-all-lts-trusty xserver-xorg-video-all-lts-trusty libgl1-mesa-dri-lts-trusty x11-xserver-utils-lts-trusty mesa-vdpau-drivers-lts-trusty libgles2-mesa-lts-trusty libglapi-mesa-lts-trusty

Manually installing xserver-xorg-lts-precise first will make sure you have all the dependencies you need. Then install the packages defined by hwe-support-status.

For you this means running the two commands...

sudo apt-get install xserver-xorg-lts-precise
hwe-support-status --verbose
sudo apt-get install linux-generic-lts-trusty xserver-xorg-lts-trusty libgl1-mesa-glx-lts-trusty linux-image-generic-lts-trusty

This issue is discussed in bug #1328264 I just hadn't read it properly :-)