Broken Link Errors

I am new to Webbuilding and SEO so I am trying to teach myself as I go and sure to be making a few mistakes.

Basically I am getting a lot of 404 errors referencing a page I dont have on my site.
After looking into my pagesource I can see the item referenced:

<!– /SEO Ultimate –>

<link rel=”alternate” type=”application/rss+xml” title=”decoplumbing.com » Feed” href=”http://www.decoplumbing.com/feed&#8221; />
<link rel=”alternate” type=”application/rss+xml” title=”decoplumbing.com » Comments Feed” href=”http://www.decoplumbing.com/comments/feed&#8221; />
<link rel=”alternate” type=”application/rss+xml” title=”decoplumbing.com » Sitemap Comments Feed” href=”http://www.decoplumbing.com/sitemap/feed&#8221; />

On an SEO audit it specifically mentions it (audit below):

This page links to the page “http://www.decoplumbing.com/comments/feed&#8221; (using the <link href (rel=”alternate”)> tag). The web server returned the error code 404 when accessing the linked page. This means that search engines cannot access the linked page, either, and that they might come to the conclusion that this page is not up-to-date.

Given the line is referenced under the SEO Ultimate title I am assuming this is causing the issue.
Please could anyone tell me how to switch this function off or how I can go about removing this line of code in order to fix this issue.

Many thanks

https://wordpress.org/plugins/seo-ultimate/