maven build problem

Hi, I change mysql connect url setting in xwiki-2.pom (local repository) from <xwiki.db.connection.url>"jdbc:mysql://localhost/xwiki?useServerPrepStmts=false"</xwiki.db.connection.url> to <xwiki.db.connection.url>"jdbc:mysql://localhost/xwiki ?useUnicode=true&amp;useServerPrepStmts=false"</xwiki.db.connection.url> then build 'xwiki-web-standard' by 'mvn install -Pxe,mysql ', get eror: [INFO] Scanning for projects... [INFO] ------------------------------------------------------------------------ [ERROR] BUILD ERROR [INFO] ------------------------------------------------------------------------ [INFO] Error building POM (may not be this project's POM). Project ID: unknown:xwiki-web-standard POM Location: E:\dev\xwiki\svnroot\xwiki-users\xwiki-platform-web\standard\pom.xml Reason: Cannot read project model from interpolating filter of serialized version. I have build successfully before this modification. Does pom file can not use the expression '&amp;' ?