I'm getting the same thing with no loot inside. I've even tried using both methods I've been shown. This is what my scripts are:
crate.sqs
_crate = _this select 0;
_dayz_wep =["Binocular_Vector","NVGoggles","ItemGPS","ItemMap"];
_dayz_mag =["Binocular_Vector","NVGoggles","ItemGPS","ItemMap"];
_dayz_bpk =["Binocular_Vector","NVGoggles","ItemGPS","ItemMap"];
{_crate addWeaponCargo [_x,100];} forEach _dayz_wep;
{_crate addMagazineCargo [_x,100];} forEach _dayz_mag;
{_crate addBackpackCargo [_x,2];} forEach _dayz_bpk;
_crate addWeaponCargo ["Binocular_Vector", 100];
_crate addWeaponCargo ["NVGoggles", 100];
_crate addWeaponCargo ["ItemGPS", 100];
_crate addWeaponCargo ["ItemMap", 100];
_crate addWeaponCargo ["ItemCompass", 100];
_crate addWeaponCargo ["ItemWatch", 100];
_crate addWeaponCargo ["ItemKnife", 100];
_crate addWeaponCargo ["ItemMatchbox", 100];
_crate = createVehicle ["AmmoBoxBig" , position player, [], 0, "NONE"];
[_crate] execVM "/scripts/crate.sqs";
sleep 120;
deletevehicle _crate;
if (true) exitWith {};
ammo.sqf: