{ "success": "false", "error": "Reference to undeclared entity 'raquo'. Line 21, position 75." }
Mushroom Lte throws an error:  { "success": "false", "error": "Reference to undeclared entity 'raquo'. Line 21, position 75." }
This indicates that the URL entered into the module that should be feeding RSS data is either invalid or is not providing data.

Try opening the URL set within the module settings inside Firefox (as this supports RSS browsing). If it fails to load, or is invalid, then determine the correct URL that will provide RSS data and update this into the module settings.
Additional Comments
It is very common for people to want to feed data from Wrodpress websites. By default, wordpress websites can provide an RSS freed of their blog posts. However this is not done without adding /feed/ to the URL at hand.

For example, if the URL of your website was: http://www.interactivewebs.com/blog/

Then the true base URL for this landing page is actually: http://www.interactivewebs.com/blog/index.php

Thus adding /feed/ becomes: http://www.interactivewebs.com/blog/index.php/feed/

This would be the URL that you enter into the Mushroom Lte Module.