Hi there,
we have found the solution if your RSS is not working in Joomla 2.5.6 and K2 2.5.7 and basic Joomla SEO is turned on with htaccess rewrite but without extra SEO component.

We hve searched a long time at the froum, and couldnt find a reason why the K2 RSS is no more working.
1.) Please make sure that your RSS settings are right at K2 options
2.) Turn off all extra SEO compontent
3.) Look to your RSS URL and then to the HTML Source code > here you have to see all rss articles but not display correctly into your web browser.

Here is the solution:
Go to your Joomla Admin > Global Config > Site >> Check if you have NO "&" into the Site Meta Description ( see image below)


Delete all special characters from Site Meta Description, like !"§$%&


Friendly regards
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