MongoDB - "Prefixed dollar ($) field" $$ hashKey "in field" Field name ". $$ hashKey \ not valid for storage. '"

I get the above error for the field when trying to update the document timesToDisplay

.

MongoDB version 2.6.7.

The whole model:

msg = {
          'name': '',
          'template': '',
          'displayDurInMilliSec': 0,
          'timesToDisplay': [],
          'images': [],
          'texts': [],
          'screen': []
       }

      

        
        
        
      

    

I am guessing I am getting the same error with other fields of array 3.

I tried using $set

it but threshold was getting the same error.

Code:

function updateMessage(msg) {
    var conditions = {_id: msg._id}
      , update = { 'name': msg.name,
                   'template': msg.template,
                   'displayDurInMilliSec': msg.displayDurInMilliSec,
                   'timesToDisplay': msg.timesToDisplay,
                   'images': msg.images,
                   'texts': msg.texts,
                   'screen': msg.screen
    }

    messageModel.update(conditions, update, callback);

    function callback(err, numAffected) {
        if (!err) console.log(numAffected)
        else console.log(err)
    }
}

      

        
        
        
      

    

EDIT: The parameter msg

is the document itself:

{ _id: '557d58abd54955480db6694f',
  name: 'msg99',
  timesToDisplay: [ { startDate: '2015-06-19T21:00:00.000Z',
                   '$$hashKey': 'object:214',
                    endDate: '2015-06-25T21:00:00.000Z',
                    daysOfTheWeek: [Object],
                    startTimeOfDay: '11',
                    endTimeOfDay: '13' } ],
 images: [],
 texts: [],
 screen: [ 1 ],
 '$$hashKey': 'object:54',
 displayDurInMilliSec: '40189',
 template: 'templates/Template2.html' }