Workplace switcher stopped working in Ubuntu 16.04
Did another search today and found this: Can't switch workspaces
The advice to go to Compiz ccsm and activate Desktop Wall fixes the problem immediately.
What a relief !
I am experiencing the same problem, so I have filed a bug on launchpad.
Try the following.
sudo apt-get install dconf-tools
dconf reset -f /org/compiz/
This worked for me