In the google webmaster tools under Site Configuration menu whenever I select sitemaps submenu I see there is error associated with feeds/posts/default. Whenever I click the link I got following errors.
Cause and Solution of the Error
There many be various reasons for which the errors have occurred.
1) Google has detected some URLs that appear to be at a higher level or different domain than the Sitemap file location. If you receive this error, try to move your Sitemap file to a higher location in your site and after logging to your webmaster tools submit the sitemap again with the specified location. For instance, if your Sitemap is listed under http://www.example.com/mysite/sitemap.xml, the following URLs are not valid for that Sitemap:
i) http://www.example.com/ - because it's at a higher level than the Sitemap
ii)http://www.example.com/yoursite/ - because it's in a directory parallel to the Sitemap
2)You should also check that the urls all begin with the same domain as your Sitemap location. For instance, if your Sitemap is listed under http://www.example.com/sitemap.xml, the following URLs are not valid for that Sitemap:
i) http://www.blogger.com - it's in the blogger.com domain rather than your example.com domain
ii) http://example.com/ - it's missing the initial www as your sitemap file/ the site you submitted in your webmaster tools had initial www.
iii) www.example.com/ - it's missing the protocol (http)
iv) https://www.example.com/ - it's using a different protocol (https rather than http)
So check your sitemap url and consider these factors. Once you follow these rules resubmit the submit url again and it should work.
If you have blogger account and you see you get above message then sign in to your blogger dashboard. Click on Settings and then click on Site Feed under Settings tab. Check the Post Feed Redirect URL. If you see your Post Feed Redirect URL is different from the sitemap url submitted to google webmaster tools then error will occur. You simply remove any URLs from the box and click "Save Settings". Just like following image.
Once you are done resubmit your sitemap in google webmaster tools.