I have been running ubuntu 14.04, then 14.10 on my Intel NUC model DN2820FYKH for months without any issues. I recently reformatted and reinstalled a fresh copy of 15.04, and after doing so I am now unable to reboot or shutdown, via terminal or from the GUI. Upon doing either, I get the purple loading screen, and there it stays. One difference I've noticed is that while shutting down, the progress bars appear to move for a while before freezing. When rebooting, they never move at all. I have to go to the box, hold down the power button, then turn it back on.
So far I have run all updates, and tried the following solution:
Ubuntu 15.04 freezing on shutdown/reset and having problem with Nvidia
This appears to be the same issue:
14.10 to 15.04 upgrade, now I can't poweroff or reboot!
update: I tried adding acpi=force
to my grub file as detailed here:
Shutdown does not power off computer
This did not fix the issue.
GRUB_CMDLINE_LINUX='acpi_enforce_resources=lax'
to GRUB and then runsudo update-grub