@finesoftMay 12.2014 — #The Crawl Errors page provides details about the URLs in your site that Google could not successfully crawl or that returned an HTTP error code.
@abnerhawkinsMay 12.2014 — #As the name suggests crawl errors are errors which Google faced at the time of crawling webpage. It could be DNS errors, server connectivity error, Robots.txt Errors and many more.
@finesoftMay 21.2014 — #Google crawl error is general error on webmaster cause crawler not able to find out your page may be possible crawler crawl your old page .