Gnome classic Alt-Tab doesn't work

Seems Application Switching is turned of by default.

To activate it you need to run the following command

ccsm

That will bring up CompizConfig Settings Manager.

• Go to the Window Management section.
• Check off ✔ Application Switcher.

Then the Alt+Tab will work.

Require installation of the compiz-plugins-extra package.

The solution in Meer Borg's answer made my computer very slow.

I instead checked the:

✔ Static Application Switcher

That also solves this problem.