Validator Exceptions in CLI

[IsThatUniqueEnough]

Not sure if this is an "issue" so I'm starting this as a discussion...

If XML validation throws an exception the output of the CLI states that the document is valid:

<validation filename="EXTENDED_Warenrechnung_kaputt.xml" datetime="2025-07-18 10:31:45">
  <xml>
    <summary status="valid"/>
  </xml>
  <summary status="valid"/>
</validation>

stderr-Output:

[main] INFO com.helger.schematron.xslt.SchematronResourceXSLTCache - Compiling XSLT instance [cpPath=/xslt/ZF_233/FACTUR-X_EXTENDED.xslt; urlResolved=true; URL=jar:file:/C:/TEMP/mustangCLI/Mustang-CLI-2.18.0.jar!/xslt/ZF_233/FACTUR-X_EXTENDED.xslt]
[main] ERROR com.helger.xml.transform.LoggingTransformErrorListener - [fatal_error] @ (1:43) Transformation fatal error (net.sf.saxon.trans.XPathException: A sequence of more than one item is not allowed as the value in 'cast as' expression (<ram:TaxTotalAmount>, <ram:TaxTotalAmount>) )
[main] ERROR org.mustangproject.validator.ZUGFeRDValidator - XML validation threw an exception
org.mustangproject.validator.IrrecoverableValidationError: A sequence of more than one item is not allowed as the value in 'cast as' expression (<ram:TaxTotalAmount>, <ram:TaxTotalAmount>)
        at org.mustangproject.validator.XMLValidator.validateSchematron(XMLValidator.java:483)
        at org.mustangproject.validator.XMLValidator.validate(XMLValidator.java:377)
        at org.mustangproject.validator.ZUGFeRDValidator.internalValidate(ZUGFeRDValidator.java:198)
        at org.mustangproject.validator.ZUGFeRDValidator.validate(ZUGFeRDValidator.java:257)
        at org.mustangproject.commandline.Main.performValidate(Main.java:482)
        at org.mustangproject.commandline.Main.main(Main.java:442)
[main] INFO org.mustangproject.validator.ZUGFeRDValidator - Parsed PDF:absent XML:valid Signature:null Checksum:0EFAC489669DBA9F2144C79F6BCB50D493477D0B Profile:urn:cen.eu:en16931:2017#conformant#urn:factur-x.eu:1p0:extended Version:2 Took:1947ms Errors:[] ErrorIDs: []

The file that produces the exception:
EXTENDED_Warenrechnung_exception.xml.txt

[jstaerk]

It is an issue, closing here, continuing as #904