Worthwhile data to review in the Navigation Summary for your website’s error pages :
- Entrance Percentage – if many of the pageviews were entrances from external sources, you might need put a 301 redirect in place to avoid the error.
- Previous Pages – since these pages are within your own site, you should be able to fix the requests. Also, if your error page URL don’t indicate the page that was requested, bad requests on your own pages can help you determine the entrance errors.
- Exit Percentage – how many people are abandoning your site after the error? This can indicate the extent of the damage.
Keep in mind that the default Web server error pages do not contain the Google Analytics tracking code (GATC), so make sure that you have specified one or more custom error pages in your Web server configuration and that these pages do contain the GATC.