Thread:Extension talk:WYSIWYG/CKeditor.body.php on line 221 Fatal error: Call to undefined method MediaWiki::getVal()

how can I fix it? I download MediaWiki 1.22.4. and  wysiwyg-1.6.0_0. when I click edit,this err is happen. when I install wysiwyg,I modify the file named CKeditor.body.php  like  https://www.mediawiki.org/wiki/Special:Code/MediaWiki/93430