GNOME: Bottom task bar is missing/blank after upgrade
It turns out that for some reason the settings for my bottom panel(taskbar) had been altered. To access the menu for the panels(top & bottom bars), I needed to hold Alt and then Right-click. This opened a little menu where I could select Add to panel... which opens another menu of things you can add to the taskbar. What I needed to add was 'Windows List', which solved my problem.
On the latest version of Kali 2.x, I had the same exact issue. Alt + Right Click
didn't do anything, but if you do the following it gets out of Kiosk mode
right click
select applications -> settings -> panel
it will say there is no panel running and are you sure you want to start one.. I clicked execute
and it stopped running kiosk mode.