Unable to load knime workflow

One of my knime workflows stopped loading when I tried opening it in Knime today. It was working fine till last time I checked it (couple of days back)

Here is the error:

java.io.IOException: Unable to parse xml: line=2: Content is not allowed in prolog.

xml: URI=java.io.BufferedInputStream@1fa9aa8b

dtd: URI=null

Also attaching error log file. Please help.

knime.log

Please note other workflows are loading successfully