Webmaster tools showing 404 error for a page that never really existed

Webmaster tools under Crawl errors shows mydomain.com/index.html as a 404 error and that it has been linked from 100 pages

there are 2 things that are wrong with that.
- I haven't had index.html but index.php almost from the start. So it has been index.php for at least 3 months now. Being index.html for just few days or so in the very beginning of the site.
- Those 100 pages that are supposed to be linking to mydomain.com/index.html are actually linking to just mydomain.com/

So where this index.html comes from?

 

it's come from others link to you. The way to sort this out is 301

 

not sure what's wrong with that.. but yes redirection is the best thing to do for that..

 

but they link to mydomain.com not mydomain.com/index.html
so that doesn't explain it

 

Sometime the weird links are come from content scraped blog. You can got them fixed by done 301 redirect from one version to the one you are preferring. This Guide could help you get the job done.

 

yeah just did that, lets see how long it takes for that to disappear from GWT

 

If that link do not exist or has been removed, then you can submit URL removal request from Google webmaster tool. You can also submit to remove complete directory.