Comment 3 for bug 1741502

This sounds like the problem I have. I did a system update on Thursday and the problems started once I rebooted. Additional problems that I have are that Alt + Tab no longer works (it should display the task list). I couldn't find any way of switching tasks except to click two or three times on the appropriate icon on the Launcher. Another problem is that Shutdown no longer works from the system menu so I shutdown using the shutdown command in a terminal. The problems switching tasks make ubuntu near unusable on my 16.04 laptop so I'm now using a spare laptop running 17.10.