Make a simple mission with one soldier and copy this into debug console:
[] spawn {
disableSerialization;
waitUntil {
waitUntil{!isNull (findDisplay 49)};
_abortButton = (findDisplay 49) displayCtrl 104;
_abortButton ctrlSetText "Abort";
_abortButton buttonSetAction "
closeDialog 0;
closeDialog 0;
uiNamespace setVariable [""BIS_fnc_guiMessage_status"", false];
_abort = [
""Do you really want to abort?"",
""Abort"",
""Yes"",
""No""
] call bis_fnc_GUImessage;
if(!_abort) exitWith {};
[""END1"",true,true] call BIS_fnc_endMission;
";
waitUntil{isNull (findDisplay 49)};
false;
};
};
Double press Esc (to refresh the screen) and press "Abort".
Your game will crash