Hi , I'm trying to add my own safe zone but it's not working i don't know what I did wrong I'm based on markers here is the script:

0 = [] spawn
{
while{true} do
{
{
if( (_x isKindOf "zombie") && _x distance (getMarkerPos "mrk_safe_zone_14") < 100) then {_x setDamage 1};
}
forEach allUnits;
sleep .1;
};
};

The script works if you spawn zombies in zeus mod but not on ravage Ambient Zombies module.
Any help to figure it out please ?