Comment 7 for bug 1623969

I'm unsure if I understand the above but I have the same problem on a fresh install of kubuntu 16.04.1 and it occurred after I did a reboot just after changing my user password via the user manager in the system settings. Having switched to the tty1 command line from the frozen kde login I noticed that ecryptfs-mount-private still only accepted my old user password to unlock my home folder. When I changed the user password back to the original one, kde login worked again. Hopefully this observation helps.