title: Fatal error: Call to undefined method Mage_Adminhtml_Model_System_Config_Source_Yesno::setAttribute() in Abstract.php on line 389
body: <p>I've looked everywhere and can't find how to fix this error. It doesn't show up in any error logs I'm aware of. I can only see it if I look at the page source. It completely stops the page from rendering half way through. How can I fix this?  </p>