Can not use action tag in a vf page

Question

There was something wrong with my page when I add an action tag to it. Don't know what went wrong. By the way I'm using this page in community site(CloudCraze). (There is nothing in the page yet)The code of the page was like this:

<apex:page sidebar="false" showHeader="false" standardStylesheets="false" applyHtmlTag="false" controller="controller"
    action="{!initAction}">
</apex:page>

The code of the controller :

public class controller{
    public controller() {
    }
    public PageReference initAction() {
        return null;
    }
}

Any help is appreciated!!!!!