Google has added a new feature to their webmaster tools. Its called “Web Crawl”.

What does it do?

It Identifies all the backlinks to your site which are pointing towards a Non-existent Page i.e. those backlinks which are broken

Consequences of linking to a Non-existent Page?

Though it doesn’t hurt much in case of your site’s SEO purpose but you are losing the effective PR juice which you deserve for your site. As Google will not rank a non-existant Page, the backlik becomes useless.
Also you will lose the important traffic which will come to your site following the backlink.

This Blog Had Zero Errors when I used web crawl on it.

Google Web Crawl