java.lang.NullPointerException
at org.apache.pdfbox.preflight.metadata.PDFAIdentificationValidation.checkConformanceLevel(PDFAIdentificationValidation.java:105)
at org.apache.pdfbox.preflight.metadata.PDFAIdentificationValidation.validatePDFAIdentifer(PDFAIdentificationValidation.java:81)
at org.apache.pdfbox.preflight.process.MetadataValidationProcess.validate(MetadataValidationProcess.java:87)
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)