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: 
What tags are installed in your GTM container? Specifically, are you using any "Custom HTML" tags? If so, I've seen the document.write() method do this to pages before. So make sure you check the "Support document.write" box underneath the code block in your tag.

Thanks
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