My embed block iframe code does not work. Any ideas?

I am trying to use an embed block on my Squarespace site to display the following iframe on a page:

<iframe style="border: 0px;" width="120" height="430" src="http://mintillustrations.theprintbar.com/publish/ifeed?s=0&t=Products&o=0&f=Arial&fs=10&bg=%23FFFFFF&fg=%23000000&c=1&cnt=3"/>

When I attempt to put the code in an embed block using the "embed data" field (not the URL field), the block displays a pixelated sad face page icon.

Does anyone have any idea why this iframe code won't work with Squarespace, or ideas on how I could make it work? 

Thanks in advance! 

To help with a specific answer, we need to see the issue first hand, which means we need you to provide a working link to your website. If the site isn't live, we need you to set a password in the visibility settings and tell us what it is. 

Without a link to the site, I'd guess that the issue is due to the non-secure URL you are using (http://). If your site is using https then the iframe must also use https. You will not be able to change the URL in the iframe because the site you are trying to embed does not support https.

Thanks for your assistance.

Here is the webpage with the embed block https://mintillustrations.com/shop

1 minute ago, MintIllustrations said:

Here is the webpage with the embed block https://mintillustrations.com/shop

That confirms that the issue is as I suspected.

I suggest you approach the other company to ask them when their site will be upgraded to be secure (SSL/HTTPS). When they allow https, the iframe will work.

The only other alternative is to downgrade your site's security - but I recommend against doing this as it's really important for security. So important in fact, that Google actually punishes websites that don’t use https by pushing them down in the rankings.