Difficulties to change settings in wt.properties.xconf

Hi there,

our users required to enable the search for empty attribute fields. The Windchill documentation states that this can be done by setting the property com.ptc.windchill.search.queryBuilder.enableNullCriteria in wt.properties.xconf to true.

I am used to edit settings with the xconfmanager tool. The command

xconfmanager -s com.ptc.windchill.search.queryBuilder.enableNullCriteria=true -t codebase\wt.properties.xconf -p

failed with a lengthy error message (see attached file).

In the wt.properties.xconf file, a comment has been inserted at the beginning:

#-*- XCONF CONTENT START -*-!-*-!-*-!-*-!-*-!-*-!-*-!-*-!-*-!-*-!-*-!-*-!-*-!-*-
# WARNING:
#
# This file has been updated by the xconfmanager tool located in,
# $(wt.home)\bin but this file is not declared by PTC as being managed
# via xconf.
#
# To ensure that your settings will be preserved the next time the 
# xconfmanager is run or an installer is used to install a new product or
# a maintenance update to the currently installed products:
#
# **** DO NOT MODIFY THE CONTENTS OF THIS FILE DIRECTLY! ****
#
# If you are configuring this installation and you wish to change a value
# from its default, edit your site-specific xconf configuration file:
# C:\ptc\Windchill_11.0\Windchill\site.xconf
# using the xconfmanager tool located in $(wt.home)\bin. You may run the
# command 'xconfmanager -h' to obtain a usage statement for this tool.

# The following properties are specified in xconfs:
# - com.ptc.windchill.search.queryBuilder.enableNullCriteria
#
#-*- XCONF CONTENT END -!-*-!-*-!-*-!-*-!-*-!-*-!-*-!-*-!-*-!-*-!-*-!-*-!-*-!-*-

So my question is: How do I properly set options in wt.properties.xconf? And how can I revert the changes?

Thank you in advance for your comments.

Best

Chris