Thread:Project:Support desk/Undefined property: DatabaseMysql::$mTrxDoneWrites in Database.php

Hi Brots, Now i have installed mediawiki-1.20.1 sucessfully. But there is a prompt on the home web: Undefined property: DatabaseMysql::$mTrxDoneWrites in Database.php.

Software details: Linux:2.6.18 mediawiki: 1.20.1 apache:2.2.3 mysql:5.5.23 php:5.5.3

Please help me to solve it. Thanks!