""" 500 JHTML ICON NOT FOUND.""" after 2.5 upgrade
go to
/home/HOME/public_html/USER/templates/***template/html/com_content/article/default.php
change this line
JHtml::addIncludePath(JPATH_COMPONENT.DS.'helpers');
to
JHtml::addIncludePath(JPATH_COMPONENT .'/helpers');
https://www.gavick.com/forums/game-magazine-joomla3/500-jhtml-icon-not-found-26651