Webmaster Tools showing over 25k Not Found URL's

[boirun03]

In my webmaster tools account they are showing over 25k url's not found and not linked from anywhere. The structure they are showing are like combined paths for 2 directories or they are adding in a duplicate directory within the structure. Like home/dir1/dir1/page.htm and this is the same for all 25k. I don't have my site linked this way or link to any of these pages. What could be going on here. Also my crawled pages per day sunk to almost nothing the past week.

[tedster]

One thing you can count on - there is a technical error here, either on your site or in Google's indexing. I know you said you do not have your site linked this way - I would add the word "intentionally" to your statement, because all kinds of funny things can happen.

I'd suggest using Xenu Link Sleuth to crawl your site and see if it runs into any malformed URLs.

[johnhh]

We had this - you will get a message on WMT saying many URL's - then a few months later a message saying you have loads of page not founds

Ours just disappeared ... worth checking as Tedster say's but we found none of the links actually existed !

[Planet13]

I had a similar problem when I made a mistake with my canonical link tag, so I would suggest you take a look to make sure that your canonical links are pointing to the correct place.

[maximillianos]

We had a bug in our code that allowed G to index literally 100k empty pages (maybe more). We never noticed it because we were not looking for it.

Run Xenu against your site. See if it uncovers any loopholes that may be causing those 404s.