I've got a crash on 0.17.77:
1. Entered into editor mode.
2. Paused the game.
3. Added, connected and set up one pushbutton.
4. Turned it on, played several ticks.
5. Repeated #4 several times.
6. Deleted the pushbutton (still on pause).
7. Crashed on the second tick after delete.
Though, I could not reproduce it, maybe I forgot some important step.

The mod Pushbutton caused a non-recoverable error.
Please report this error to the mod author.

Error while running event pushbutton::on_tick (ID 0)
LuaConstantCombinatorControlBehavior API call when LuaConstantCombinatorControlBehavior was invalid.
stack traceback:
pushbutton/control.lua:5: in function <pushbutton/control.lua:1>
stack traceback:
[C]: in function 'newindex'
__pushbutton/control.lua:5: in function <pushbutton/control.lua:1>