XML : Auto generate a class from a xml file

I'm working on creating a class file from the xml file but xsd is complaining saying "Cannot add a nested relation or an element column to a table containing a simplecontent column" and here is the sample xml. My actual xml file is very long with over 30MB and I can't edit the nodes manually and wondering if there is a alternate solution ?

  <SpeedLineMenu>    <Children>      <ValueMealTreeRoot>        <Name Type="String">Value Meals</Name>        <SequenceID Type="Integer">0</SequenceID>        <IsActive Type="Boolean">true</IsActive>        <Children>          <Group>            <Name Type="String">Lunch Specials</Name>            <SequenceID Type="Integer">3872</SequenceID>            <IsActive Type="Boolean">true</IsActive>            <Caption Type="String">Lunch Specials</Caption>            <Children>              <ValueMeal></ValueMeal>            </Children>           </Group>        </Children>       </ValueMealTreeRoot>    </Children>  </SpeedLineMenu>