The RPi very likely needs a firmware upgrade, which isn't yet in your LE installation.
Which LibreELEC version are you trying to install?
Hmm yeah, didn't actually try the old rpi-update, will try that tomorrow.
Using the latest stable release - LibreELEC-RPi2.arm-7.0.2.img.gz
Looks like back in September the Pi 2 got a chip update (now the same as the Pi 3, but underclocked) - New Raspberry Pi 2B 1.2 with Pi3 BCM2837 Processor – RasPi.TV
Since this update the "new" Pi 2's no longers work with LibreELEC either flashing the .img file from a direct download or via the NOOBs installer.
The installation (via NOOBs) completes but on reboot the system doesn't load and you get 3 or 4 fast flashes of green led followed by 3 or 4 slow flashes of green led. This flash cycle just continues and the system never loads.
Same flash cycle on boot when installed via .img
