Workaround #1: I can confirm that on Lenovo P70 Mobile Workstation running Artful Aardvark 17.10 an upgrade to kernel 4.13.6 or higher prevented the hang on "wlp4s0: failed to remove key" (although as mentioned the error still appears in the shutdown sequence).
Workaround #2 I also found that if I went into /etc/default/grub" and removed "quiet splash", i.e. change: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" to: GRUB_CMDLINE_LINUX_DEFAULT="" and then run: sudo update-grub and reboot the hang also goes away without any need to upgrade to a higher kernel version (i.e. this fix works with the latest pushed kernel: Linux athens 4.13.0-16-generic #19-Ubuntu SMP -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1720930 Title: wlp3s0: failed to remove key (1, ff:ff:ff:ff:ff:ff) from hardware (-22) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1720930/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs