Press the PrtScrn key while typing a chat reply in the message tray.


    JS ERROR: !!!   Exception was: Error: 66 is not a valid value for enumeration KeyBindingAction
    JS ERROR: !!!     lineNumber = '0'
    JS ERROR: !!!     fileName = 'gjs_throw'
    JS ERROR: !!!     message = '66 is not a valid value for enumeration KeyBindingAction'
    JS ERROR: !!!     stack = 'Error("66 is not a valid value for enumeration KeyBindingAction")@:0
("66 is not a valid value for enumeration KeyBindingAction")@gjs_throw:0
@:0
_globalKeyPressHandler([object _private_Clutter_Stage],[object _private_Clutter_Event])@/home/jmccann/gnome-shell/source/gnome-shell/js/ui/main.js:331
Error("Chained exception")@:0
("Chained exception")@gjs_throw:0


In one case (while testing Marina's latest style update so might be unrelated) this seemed cause a stuck grab and I couldn't interact with any windows on screen.  Had to kill the shell from a terminal.