My desktop has locked twice when running 929 in fullscreen mode. Once when I was using Glyphs, Glyphs froze, and the computer kept running but the keyboard and mouse were unresponsive. That time I was able to log in via SSH and kill Glyphs, but the keyboard and mouse remained unresponsive until I logged in via SSH and killed the loginwindow process. A second time the computer came out of sleep with Glyphs in fullscreen and the display would not wake. That time I cycled power to save time. My Mac is running version 10.11.6.
I’m not certain that this is a Glyphs bug, but I’m not running any other software that is a likely culprit.