Comment 293 for bug 43961

Adding "rmmod snd_hda_intel" to the end of /etc/default/halt worked on my LG LW20 Express Laptop.

If you have the same kind of computer, just write this in a terminal window:

sudo gedit /etc/default/halt

enter your password (nothing will be shown, not even *, but it's still being written)

In the gedit window, add "rmmod snd_hda_intel" without the "" to the end of the last row.

Save.

'Shut down' and 'Hibernate' now works! Thanks StevenMcCoy for finding a solution and posting it here!