This is to all the Windows 10 users out there that are having this issue. My computer is a Acer desktop computer and IS up-to-date on all the windows updates.
Behavior - You lock your computer out / or it goes to the lock screen, after sometime of inactivity... there is just the wallpaper, no login option, or shutdown buttons, no keyboard control (ex. alt, ctrl, delete) - nothing works and you are left just staring at a blank wallpaper.
Fix - Hit the shift key 5 times it will bring up the 'sticky note' message asking if you want to turn sticky notes on; You then will be able to 'alt, ctrl, delete' and get your Windows login screen back!!!