xjc type definition name resolution error

I am running into troubles when wanting to compile my XSDs (which I am not the author of) with XJC.

Specifically, I get the error (there are actually more like these):

 [ERROR] src-resolve: Cannot resolve the name "ifopt:CountryRefStructure" to a(n) 'type definition' component.
   line 131 of file:/E:/ansdef/schema/siri-1.3/siri/siri_situationIdentity-v1.1.xsd

That is strange since the mentioned file (siri_situationIdentity-v1.1.xsd) refers to another XSD where the suspicious type is declared.

I tried several things

• switch Java version to get different xjc
• tried some different xjc directly from java.net
• applied some modifications to the files so that the currently applied JAXB workarounds regarding includes/imports are removed
• tried to use the whole directory with dependent schemas as target for xjc
• Altova XMLSpy Java code generation works well without errors (but is no way to go for me)

None of them worked.

Does anybody have a clue what the error message is caused by? I don't see the point. You may get all the XSDs directly from here: Verband Deutscher Verkehrsunternehmen (VDV) - Ist-Daten-Schnittstellen

The command line I tried (amongst others) was:

xjc -readOnly -d generated -npa -target 2.1 -verbose VDV453_incl_454_V2.3e.xsd

Any help or hint is greatly appreciated.

Regards

The solution here was to use the -nv switch to disable strict validation.