Can't generate java POJO classes using MathML

Hi -

We use Brightspace Learning modules and I'm trying, given the xsd   imsqti_v2p1.xsd  create Java classes.  This is
the last error and I can't seem to fix it -

parsing a schema...
[ERROR] Property "MiOrMoOrMn" is already defined. Use <jaxb:property> to resolve this conflict.
  line 132 of http://www.w3.org/Math/XMLSchema/mathml2/presentation/scripts..xsd

[ERROR] The following location is relevant to the above error
  line 138 of http://www.w3.org/Math/XMLSchema/mathml2/presentation/scripts..xsd

Failed to parse a schema.

Here is the first line of imsqti_v2p1.xsd

<xs:schema xmlns:jxb="http://java.sun.com/xml/ns/jaxb" jxb:version="2.1"
xmlns="http://www.imsglobal.org/xsd/imsqti_v2p1" xmlns:xi="http://www.w3.org/2001/XInclude"
xmlns:m=http://www.w3.org/1998/Math/MathML


I can find the version 2 xsd for MathMl and it has the hint of where the error is - the main resource seems to
call these "helper" xsd's

<!-- Presentation -->
<xs:include schemaLocation="presentation/common-types.xsd"/>
<xs:include schemaLocation="presentation/common-attribs.xsd"/>
<xs:include schemaLocation="presentation/characters.xsd"/>
<xs:include schemaLocation="presentation/tokens.xsd"/>
<xs:include schemaLocation="presentation/scripts.xsd"/>      error

Since this is called locally by http://www.w3.org/1998/Math/MathML I'd have to download
it all as a zip and fix it (or somehow fix it in bindings.xjb which I use)

so I guess I'm going to have to cancel the project?  I'm running out of things to try ...

Any insight appreciated

Tom