Well it’s important to fix, because it will affect your page rank and use webmaster tools to fix it as soon as possible, I had a friend which have errors on its link but they disregard it until one day their site didn’t appear on google results, again use the webmaster tools to fix it.

Broken links affects the quality of your site. If you have a broken link it is more likely that your visitors will close the tab since the thing that they are looking for is not there. I suggest open your website on a different tab not the owner's page but on the user end and check the links one by one. It will require some effort but it is the best since you will experience the end-user-feel. You might even discover room for improvements.

You can use Google webmaster tool to find and fix broken links. To find the broken link report from your dashboard, click on your web site link, then Diagnostics, then Web Crawl, then Not Found to see the broken links report. You should check this report regularly.

Use these tools to find the broken links

Broken Link Checker | Find Broken Links on website

Free Broken Link Checker - checks your website for bad links / dead links online.

After finding the broken links, fix it quickly..