Updated from 16.04 to 16.10; the keyboard and mouse no longer works after getting to the lock screen

Solution 1:

I had the same issue today and found this bug report.

The problem seems to be, that during update process they forget to install/update the package xserver-xorg-input-all!

So these instructions worked for me on my thinkpad p51s notebook with a little modification:

1. Press a Shift key during boot to get the GRUB menu.
2. In GRUB, select Advanced Options, then the first kernel with the recovery mode.
3. Select "Network" to get network access (needed for package installation)
4. Select "Drop to root shell"
5. Press Enter to confirm.
6. On my system not needed because, the filesystem was mounted rw, but if needed then mount -o rw,remount /.
7. Install the needed package: apt install xserver-xorg-input-all (and the message that they need to uninstall 16.04 packages!)
8. Press Ctrl+D to leave the root shell.
9. Select resume boot from the menu.
10. Now I could only log into console.
11. sudo reboot

After reboot my ThinkPad's mouse and keyboard and the external mouse and keyboard worked fine!

Solution 2:

I had the same problem. I fixed it using only my trackpad. I had to enable the onscreen keyboard from System Settings > Universal Access > Typing, then opened a terminal and ran sudo apt install xserver-xorg-input-all. After a restart, everything was fine. A little tedious but it's the simplest solution I've seen.