         transform: null
 
       unless target
-        Log.error "Document's '#{ id }' field '#{ @sourcePath }' is referencing a nonexistent document '#{ value._id }'"
+        Log.error "Document '#{ @sourceDocument.Meta._name }' '#{ id }' field '#{ @sourcePath }' is referencing a nonexistent document '#{ value._id }'"
         # TODO: Should we call reference.removeSource here? And remove from reverse fields?
         return
 

      return if _.isNull(value) and not @required

      # TODO: This is not triggered if required field simply do not exist or is set to undefined (does MongoDB support undefined value?)
      Log.error "Document's '#{ id }' field '#{ @sourcePath }' was updated with an invalid value: #{ util.inspect value }"
      return

    # Only _id is requested, we do not have to do anything

    if field instanceof globals.Document._ObservingField
      if field.ancestorArray and name is field.ancestorArray
        unless _.isArray value
          Log.error "Document '#{ @sourceDocument.Meta._name }' '#{ id }' field '#{ name }' was updated with a non-array value: #{ util.inspect value }"
          return
      else
        value = [value]
