NPE in PdfaExtensionHelper.populateSchemaMapping

java.lang.NullPointerException
	at org.apache.xmpbox.xml.PdfaExtensionHelper.populateSchemaMapping(PdfaExtensionHelper.java:198)
	at org.apache.xmpbox.xml.DomXmpParser.parse(DomXmpParser.java:202)
	at org.apache.xmpbox.xml.DomXmpParser.parse(DomXmpParser.java:114)
	at org.apache.pdfbox.preflight.process.MetadataValidationProcess.validate(MetadataValidationProcess.java:67)
	at org.apache.pdfbox.preflight.utils.ContextHelper.callValidation(ContextHelper.java:73)
	at org.apache.pdfbox.preflight.utils.ContextHelper.validateElement(ContextHelper.java:88)
	at org.apache.pdfbox.preflight.PreflightDocument.validate(PreflightDocument.java:168)
	at org.apache.pdfbox.util.TestPDFToImage.doTestFile(TestPDFToImage.java:337)
	at org.apache.pdfbox.util.TestPDFToImage.testRenderImage(TestPDFToImage.java:382)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at junit.framework.TestCase.runTest(TestCase.java:176)
	at junit.framework.TestCase.runBare(TestCase.java:141)
	at junit.framework.TestResult$1.protect(TestResult.java:122)
	at junit.framework.TestResult.runProtected(TestResult.java:142)
	at junit.framework.TestResult.run(TestResult.java:125)
	at junit.framework.TestCase.run(TestCase.java:129)
	at junit.framework.TestSuite.runTest(TestSuite.java:255)
	at junit.framework.TestSuite.run(TestSuite.java:250)
	at junit.textui.TestRunner.doRun(TestRunner.java:116)
	at junit.textui.TestRunner.start(TestRunner.java:183)
	at junit.textui.TestRunner.main(TestRunner.java:137)
	at org.apache.pdfbox.util.TestPDFToImage.main(TestPDFToImage.java:432)