A Google Webmaster Help thread has one webmaster complaining that the crawl errors report in Google Webmaster Tools is not showing him the details of those errors.
Specifically, Google is telling him he has 54 errors related to page not found (404 status codes). He wants to review those specific pages to see if it an issue with the site or server or if it is done right. Having 404s are not bad if it is done on purpose.
But when the webmaster looks for the details it is missing. Here is a screen shot:
Google's John Mueller confirmed the bug in the thread and said:
Just a short update -- it looks like this is a bug, the team has been working on a fix for this, but it might be a few weeks before it's live. Thanks for your patience & sorry for the inconvenience.
I personally do not see this issue but I am sure it is happening to others.
Forum discussion at Google Webmaster Help.