404 Error on Blog Pages that Look Like Loading Fine

[theLotter]

There was recently a huge increase in 404 errors on Yandex Webmasters corresponding with a drop in rankings.

Most of the pages seem to be from my blog (which was updated around the same time).

When I click on the links from Yandex the page looks like it is loading normal, expect that it has the following message from the Facebook plugin I am using for commenting

Any ideas about what the problem is or how to fix it?

Critical Errors That Must Be Fixed

| Bad Response Code: | URL returned a bad HTTP response code. |

Open Graph Warnings That Should Be Fixed

| Inferred Property: | The 'og:url' property should be explicitly provided, even if a value can be inferred from other tags. |
| Inferred Property: | The 'og:title' property should be explicitly provided, even if a value can be inferred from other tags. |
| Small og:image: | All the images referenced by og:image should be at least 200px in both dimensions. Please check all the images with tag og:image in the given url and ensure that it meets the recommended specification. |

[ChadBreezy]

What CMS platform are you using?

Also do you have your mod rewrites in place on your .htaccess file?