Question: I inserted a Google Tag Manager code snippet below the body tag but my website will only display a blank white page. When I remove it, the page displays correctly.

```
<!-- Google Tag Manager -->
<noscript>
<iframe src="//www.googletagmanager.com/ns.html?id=GTM-XXXXXX" height="0" width="0" style="display:none;visibility:hidden">
</iframe>
</ noscript> 
<script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start': new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0], j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src= '//www.googletagmanager.com/gtm.js?id='+i +dl;f.parentNode.insertBefore(j,f); })(window,document,'script','dataLayer','GTM-XXXXXX');
</script> 
<!-- End Google Tag Manager -->

```

Answer: 
This could be security rules on your firewall. Many web application firewalls will block 0- width frames to block potential code injection vectors.

Try removing the 'style="display:none;visibility:hidden"' attribute and giving your iframe a height and a width of 100.

If that works, then probably some security system somewhere is blocking the iframe, you can normally fix this by moving the iframe styles out to an external stylesheet like this:

```
<noscript>
  <iframe src="//www.googletagmanager.com/ns.html?id=GTM-XXXXXX" class ="gtmIframe">
  </iframe>
</ noscript>...

```

and in your stylesheet:

```
.gtmIframe {
  width:0;
  height:0;
  display:none;
  visibility:hidden;
}

```
I found the solution of these.

They change something in the URL

In the blank frame <https://www.googletagmanager.com/>**ns.html?id=G**TM-XXXXXXX"

and the Iframe who really works is with these

<https://www.googletagmanager.com/>\*\*gtm.js?id=\*\*GTM-XXXXXXX 

Let me know if they work for you