For me it is on start up, meaning I can't log in at all and access settings etc. I have seen a similar issue resolved on other posts except on those the issue only occurs after waking from sleep. The touchscreen, touch-pad, mouse and keyboard are all working.
When starting up, after hitting any key on the screen with today's date which would normally cause the password prompt to appear, there is no text box to type in a password or pin, the sign-in screen is just the background pic and three items in the lower right: network, accessibility and power.
