create typecode from xml error processing tag "include"

I am trying to use the .NET create_tc_from_xml_file class to generate type codes from XML and I receive the following error in the console: 

RTIXMLParser_onStartTag:Parse error at line 3: Error processing tag 'include'
RTIXMLParser_parseFromFile:Parse error in file 'C:\XMLDataStruct\thisModule.xml'
DDS_XMLTypeCodeParser_parse_from_file:Error parsing XML
DDS_TypeCodeFactory_create_tc_from_xml_file:!error parsing types file

The XML files were generated from IDL using rtiddsgen, and the includes are at the top of the XML:

<types xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="c:/rti_connext_dds-5.2.3/bin/../resource/app/app_support/rtiddsgen/schema/rti_dds_topic_types.xsd">
<include file="headerInfo.xml"/>
<module name="body_stuff">
<struct name= "this_module_T">
...
</struct></module></types>

I'm using rti connext 5.2.3 and the nddsdotnet451 dll v1.6.1.1 in my .net project. The tc definition works if I have all the types in one large XML. However this isn't a scalable solution as I have potentially several thousand types.