Fixing managed meta data navigation problem

I have the following :-

1. SharePoint server 2013 web application.


2. the web application contains two site collections of type enteprise wiki.


3. i have enabled metadata navigation for the two site collection, and i enable Tree view.


4. the result is that i got my managed metadata on the left site of my screen, as follow:-

5.but if i click on a term (for example Hardware) it will not filter the pages, instead the current page will reload.

i find the following link which talks about the same problem link. but i am not sure how i can add this method to my site collections:-

public class CustomWikiPageBase : PublishingLayoutPage
{
    protected override void OnInit(EventArgs e)
    {
        if (!String.IsNullOrEmpty(Request.QueryString["TreeField"]) 
            && !String.IsNullOrEmpty(Request.QueryString["TreeValue"]))
        {
            Response.Redirect(String.Format("{0}?TreeField={1}&TreeValue={2}",
                SPContext.Current.ListItem.ParentList.DefaultViewUrl,
                Request.QueryString["TreeField"],
                Request.QueryString["TreeValue"]));
        }
        else if (!String.IsNullOrEmpty(Request.QueryString["TreeField"]))
        {
            Response.Redirect(String.Format("{0}?TreeField={1}",
                SPContext.Current.ListItem.ParentList.DefaultViewUrl,
                Request.QueryString["TreeField"]));
        }
        base.OnInit(e);
    }
}

i mean should i create a new sandbox solution, farm solution, or visual web part inside visual studio ? and how i can deploy the solution to my web application, can anyone advice on this please ?