17.1 Wlp6s0: failed to remove key (1, ff:ff:ff:ff:ff:ff) from hardware (-22)

I was running gnome 17.04 with no issues. I clean installed Ubuntu 17.1 and everything is fine except on shutdown / reboot it hangs with the following error. Only way to turn off is to hard power cycle which may be bad for hardware. How can I troubleshoot this?

Wlp6s0: failed to remove key (1, ff:ff:ff:ff:ff:ff) from hardware (-22)
Wlp6s0: failed to remove key (2, ff:ff:ff:ff:ff:ff) from hardware (-22)

3 ways to fix this problem:

First way: If you don't wanna make change to grub or changing the grub create other problems or you don't wanna upgrade the kernel:

• Everytime when you see that error after turning off the pc,just press alt+F7.

Second way: Removing "quiet splash" from the parameters in grub:

• gksudo gedit /etc/default/grub

  Change:

  GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
  

  To:

  GRUB_CMDLINE_LINUX_DEFAULT=""
  

  Then run:

  sudo update-grub
  reboot
  

Third way:

• Upgrade to kernel 4.13.6 or higher.

I'm having this same issue, I'd be interested to see what the resolution is. I believe disconnecting from the Wireless connection will allow you to shut down gracefully if you haven't found out, but I'm not entirely sure how to resolve it either.

EDIT: Looks like this is resolved in a new kernel version, but I'd be interested to know if a fix exists.

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1720930

I could not fix this issue at all using any solutions given, disabling wifi card options via /etc/modprobe.d/iwlwifi.conf, nothing worked.

What worked for me was changing the MAC address on the actual wifi connection. Somehow something must have been caching that and associating it with some bad wifi / connection state, even after reboot. Maybe it was my router, but it's very weird.