If I run the cli with the -h option, the json output runs on the following error message.

SEVERE: class java.lang.Double cannot be cast to class java.lang.String (java.lang.Double and java.lang.String are in module java.base of loader 'bootstrap')
java.lang.ClassCastException: class java.lang.Double cannot be cast to class java.lang.String (java.lang.Double and java.lang.String are in module java.base of loader 'bootstrap')
at edu.harvard.hul.ois.jhove.handler.JsonHandler.showScalarProperty(JsonHandler.java:726)
at edu.harvard.hul.ois.jhove.handler.JsonHandler.showProperty(JsonHandler.java:658)
at edu.harvard.hul.ois.jhove.handler.JsonHandler.showListProperty(JsonHandler.java:790)
at edu.harvard.hul.ois.jhove.handler.JsonHandler.showProperty(JsonHandler.java:662)
at edu.harvard.hul.ois.jhove.handler.JsonHandler.showListProperty(JsonHandler.java:790)
at edu.harvard.hul.ois.jhove.handler.JsonHandler.showProperty(JsonHandler.java:662)
at edu.harvard.hul.ois.jhove.handler.JsonHandler.show(JsonHandler.java:439)
at edu.harvard.hul.ois.jhove.RepInfo.show(RepInfo.java:563)
at edu.harvard.hul.ois.jhove.JhoveBase.process(JhoveBase.java:649)
at edu.harvard.hul.ois.jhove.JhoveBase.process(JhoveBase.java:576)
at edu.harvard.hul.ois.jhove.JhoveBase.process(JhoveBase.java:576)
at edu.harvard.hul.ois.jhove.JhoveBase.process(JhoveBase.java:576)
at edu.harvard.hul.ois.jhove.JhoveBase.process(JhoveBase.java:576)
at edu.harvard.hul.ois.jhove.JhoveBase.dispatch(JhoveBase.java:479)
at edu.harvard.hul.ois.jhove.Jhove.main(Jhove.java:265)

XML output works, but looks a bit damaged:

<x:xmpmeta xmlns:x="adobe:ns:meta/"> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"> <rdf:Description xmlns:pdfaid="http://www.aiim.org/pdfa/ns/id/" rdf:about=""> <pdfaid:part>3</pdfaid:part> <pdfaid:conformance>B</pdfaid:conformance> </rdf:Description> <rdf:Description xmlns:dc="http://purl.org/dc/elements/1.1/" rdf:about=""> <dc:title> <rdf:Alt> <rdf:li lang="x-default"/> </rdf:Alt> </dc:title> </rdf:Description> <rdf:Description xmlns:xmp="http://ns.adobe.com/xap/1.0/" rdf:about=""> <xmp:CreatorTool>Konik Library</xmp:CreatorTool> <xmp:CreateDate>2021-11-12T10:11:11+01:00</xmp:CreateDate> </rdf:Description> <rdf:Description xmlns:pdf="http://ns.adobe.com/pdf/1.3/" rdf:about=""> <pdf:Producer>Konik Library</pdf:Producer> </rdf:Description> </rdf:RDF> </x:xmpmeta>