My computer was interrupted while upgrading from 14.04 to 16.04. Afterward I rebooted and ran
sudo dpkg --configure -a
and rebooted again. Now, when prompted for my password on startup, nothing I enter works. I've checked caps lock and num lock and typed carefully, and have never mucked around with different keyboards. Indeed, navigating to GRUB and typing there, everything I type looks as expected.
Attempting to run from recovery mode leads to this exchange:
Please unlock disk sda5_crypt:
(I enter password)
Failed to setup dm-crypt key mapping for device /dev/disk/by-uuid/[some numbers]
Check that kernel supports aes-xts-plain64 cipher (check syslog for more info).
cryptsetup: cryptsetup failed, bad password or options?
It's not clear to me how to fix this (apparent) issue with the kernel without being able to access a normal command line.