Error (E_VALIDATION) :: 1 attribute is invalid

Question

I'm trying to update one line using sails-orientdb, this way:

      CommentModel.update({
        _id: req.body.reply.commentId
      }, comment).exec(function (err, reply) {
        // *** LOG: LOOK BELOW
        console.log(comment, req.body.reply.commentId, reply);
        // ***
        if (err)
          return next(err);
        UserModel.findOne({
          id: reply.author
        }).exec(function (err, user) {
          reply.author = user.toJSON();
          res.json({
            success: !err,
            reply: reply
          });
        });
      });

comment: { author: '#16:0', node: '#30:13', _id: '0dcb0fb8-35e9-4117-87e9-33e2ac21e0e0', body: 'lkjnn', replies: '[object Object]', createdAt: '2015-07-21T08:50:52.000Z', updatedAt: '2015-07-21T08:50:52.000Z', id: null }

req.body.reply.commentId: 0dcb0fb8-35e9-4117-87e9-33e2ac21e0e0

reply: undefined

But, I'm getting this error message:

Error (E_VALIDATION) :: 1 attribute is invalid

How to fix this, please? What's wrong?