XSD validation fails to load with `Nokogiri::XML::SyntaxError: complex type 'fallbackType': The content model is not determinist.`

[Ryan Taylor]

Nokogiri! 

I've always had great results with nokogiri, but I'm a but flummoxed on this particular issue.

I've just loaded up Nokogiri in the hopes that I can validate some XML files against their referenced XSDs.

I loaded up the file and attempted to load the first referenced XSD.

The XSD fails to load as a schema, but loads fine in the XML parser.

```

Nokogiri::XML.Schema(File.read("imsqti_v2p2.xsd"))

```

which returns: 

```

Nokogiri::XML::SyntaxError: complex type 'fallbackType': The content model is not determinist.

from /var/lib/gems/2.3.0/gems/nokogiri-1.6.8/lib/nokogiri/xml/schema.rb:37:in `from_document'

```

I would expect this to not error out. 

I am reaching out to the parent organization regarding this XSD and if this is a viable path, but it feels like this shouldn't fail.

Does anyone have tips for determining why this is bombing out on me?

Cheers,

Ryan