A little bit question, did you include the _id field into your SimpleSchema ?
If the answer is no ! and if you use Collection2, did you check the _id argument into your methods ?
Example :
equipments.update': (equipmentId, equipment) => {
check({ _id: equipmentId }, Equipments.schema.pick('_id'));
check(equipment, Equipments.schema.omit('_id'));
// ...
},
Thanks :-) Aurélien