Comment 13 for bug 1443853

Re: "I note that the person asking the question seemingly never bothered to create an Ubuntu bug, so it can't have been that important to them." That's not actually a safe assumption at all. Many people are on the clock and are not paid to file bug reports for the rest of the world. As soon they find a work-around that deals with the problem temporarily and locally, they move on. This problem has been reported world-wide in multiple circumstances, and is still happening with 16.04. It just happened to me right now (with the Xubunutu 16.04.1 ISO in a VirtualBox VM). The Right-Ctrl F1 and Right-Ctrl F7 (or "Host" F1, "Host" F7, if you've redefined the "Host" key) trick worked for me in this case, so I'm done with it and getting back to work. It is possible I (or someone in my situation) might remember to try to replicate and debug this problem further for everyone, on a VM at home, on our own time. But Canonical cannot depend on this happening. It's a "bad administrator experience" issue that should be dealt with like any other serious bug.