Exception while simulating the effect of invoking "'' Error: When the validation object contains mongo operators, you must set the modifier option to true

[miki11]

How to fix error "Exception while invoking method 'actionFail' Error: When the validation object contains mongo operators, you must set the modifier option to true"

collection import SimpleSchema from 'simpl-schema'; ActionLogsFail = new Mongo.Collection('actionLogsFail'); let SchemaActionLogFail = new SimpleSchema({ "module":{ type:String, index:true, optional: true, label:"Module Name" }, "action":{ type:String, index:true, optional: true, label:"Action Name" }, "created_at":{ type: Date, optional: true, label: "Date Create added by system", …

There is another question about the same issue, but I really couldn’t get it.

Could someone explain more about this error?

Exception while simulating the effect of invoking "'' Error: When the validation object contains mongo operators, you must set the modifier option to true

Set modifier option to true … how and where that would be?
Thank you!