Thread:Project:Support desk/Unexpected non-MediaWiki exception encountered, of type "Exception" /extensions/yambe/yambe.php:553

I have installed mediawiki latest verison 1.20.. I am receiving the following below error when I click this link "http://edn-wki-02/assyst10SP4Wiki/index.php/Lucene_Operators_in_assyst" Can any one please help to rectify the issue

Unexpected non-MediaWiki exception encountered, of type "Exception" exception 'Exception' with message 'String could not be parsed as XML' in /var/www/assyst10SP4Wiki/extensions/yambe/yambe.php:553 Stack trace:
 * 1) 0 /var/www/assyst10SP4Wiki/extensions/yambe/yambe.php(553): SimpleXMLElement->__construct('<?xml version='...')
 * 2) 1 /var/www/assyst10SP4Wiki/extensions/yambe/yambe.php(399): yambeUnpackTag(': '''extensionSubstitution(Array, Object(PPFrame_DOM))
 * 7) 6 /var/www/assyst10SP4Wiki/includes/parser/Parser.php(3043): PPFrame_DOM->expand(Object(PPNode_DOM), 0)
 * 8) 7 /var/www/assyst10SP4Wiki/includes/parser/Parser.php(1141): Parser->replaceVariables( internalParse( parse( doWork
 * 12) 11 /var/www/assyst10SP4Wiki/includes/Article.php(631): PoolCounterWork->execute
 * 13) 12 /var/www/assyst10SP4Wiki/includes/actions/ViewAction.php(37): Article->view
 * 14) 13 /var/www/assyst10SP4Wiki/includes/Wiki.php(427): ViewAction->show
 * 15) 14 /var/www/assyst10SP4Wiki/includes/Wiki.php(304): MediaWiki->performAction(Object(Article))
 * 16) 15 /var/www/assyst10SP4Wiki/includes/Wiki.php(536): MediaWiki->performRequest
 * 17) 16 /var/www/assyst10SP4Wiki/includes/Wiki.php(446): MediaWiki->main
 * 18) 17 /var/www/assyst10SP4Wiki/index.php(59): MediaWiki->run
 * 19) 18 {main}