This topic has been raised in past.
I am raising it again after going through all possible solution.
I have checked previous threads on this error but could not solve problem.
WordPress version - 3.5.1
Theme - TwentyTwelve (Was using thematic child theme but switched to TwentyTwelve to see if customization is causing problem)
Plugins - Removed all
I am having problem at http://www.infoupdates.in/feed
Error message is
XML Parsing Error: XML or text declaration not at start of entity
Line Number 2, Column 1:<?xml version="1.0" encoding="UTF-8"?>
Any help on this. Only thing left is to try new install.