waitUntil errors

[barman75]

Error Undefined behavior: waitUntil returned nil. True or false expected.
17:05:28 In last 10000 miliseconds was lost another 29 these messages.
17:05:28 File mpmissions__cur_mp.altis\CREATE\createSupplyBox.sqf..., line 174
17:05:38 Error in expression < {
sleep 1;
!(isNull attachedTo _crate) OR
!(_marker in markerSupplyCrates)
};

Error position: <OR
!(_marker in markerSupplyCrates)
};

[wurzel0701]

That one seems to be on me, but I will need further infomation, not sure what actually happens

[barman75]

⚠ Since Arma 3 v1.93.145618 returning anything other than true or false from condition will result in appropriate type error.
https://community.bistudio.com/wiki/waitUntil