Aldeed/meteor-collection2 autoValue throwing error

I am trying to use autoValue in my schema

Posts.schema = new SimpleSchema({
    title: { type: String },
    description: { type: String },
    posted: { type: Date,
        autoValue: function (){
            return new Date;
        },
    },
    likes: { type: Number, defaultValue: 0, optional: true },
    dislikes: { type: Number, defaultValue: 0, optional: true, },
    author: { type: AuthorSchema },
    votes: { type: [AuthorSchema], optional: true }
});

Posts.attachSchema(Posts.schema);

I am using this schema for validations here:

export const addPost = new ValidatedMethod({
    name: 'Posts.addPost',
    validate: Posts.schema.validator(),
    run(post) {
        if (!this.userId)
            throw new Meteor.Error('403', 'You must be logged-in to reply');
        Posts.simpleSchema().clean(post);

        Posts.insert({
            title: post.title,
            description: post.description,
            author: {
                userId: this.userId,
                vote: 0
            }
       });
    }
});

It does not work. I get an error message

Posted is required [validation-error]

Am i doing something wrong? Do i need to make Posted field optional?

I tried to change the insert method by providing default value for posted: new Date(). Did not work either. Please help.