Simulink PLC Coder's bug?Generated xml file does not meet the PLCopen xsd

    I'm Planning to use Simulink PLC Coder(Matlab 2013a) to Generate ST program,then import to OpenPCS(A PLC Proraming IDE).The xml file is generated,but error occurred while import to OpenPCS.Then I wonder if the xml file that Simulink PLC Coder generated is not meet PLCopen's XSD.The Validate result show that the xml can not be validated,err shows :unkown element 'xhtml'.I was worng? Or Simulink PLC Coder's bug? Or other reason? Thanks for your answer!