java.lang.ClassCastException: org.hl7.fhir.r5.comparison.ResourceComparer$PlaceHolderComparison cannot be cast to org.hl7.fhir.r5.comparison.ProfileComparer$ProfileComparison
	at org.hl7.fhir.r5.comparison.ProfileComparer.checkAddTypeUnion(ProfileComparer.java:599)
	at org.hl7.fhir.r5.comparison.ProfileComparer.unionTypes(ProfileComparer.java:536)
	at org.hl7.fhir.r5.comparison.ProfileComparer.compareElements(ProfileComparer.java:228)
	at org.hl7.fhir.r5.comparison.ProfileComparer.compareChildren(ProfileComparer.java:329)
	at org.hl7.fhir.r5.comparison.ProfileComparer.compareElements(ProfileComparer.java:245)
	at org.hl7.fhir.r5.comparison.ProfileComparer.compare(ProfileComparer.java:147)
	at org.hl7.fhir.r5.comparison.ComparisonSession.compare(ComparisonSession.java:97)
	at org.hl7.fhir.igtools.publisher.comparators.PreviousVersionComparator.finishChecks(PreviousVersionComparator.java:262)
	at org.hl7.fhir.igtools.publisher.Publisher.checkConformanceResources(Publisher.java:4951)
	at org.hl7.fhir.igtools.publisher.Publisher.loadConformance(Publisher.java:4850)
	at org.hl7.fhir.igtools.publisher.Publisher.createIg(Publisher.java:1051)
	at org.hl7.fhir.igtools.publisher.Publisher.execute(Publisher.java:901)
	at org.hl7.fhir.igtools.publisher.Publisher.main(Publisher.java:10439)
	at org.hl7.fhir.igtools.publisher.utils.PublicationProcess.runBuild(PublicationProcess.java:332)
	at org.hl7.fhir.igtools.publisher.utils.PublicationProcess.doPublish(PublicationProcess.java:231)
	at org.hl7.fhir.igtools.publisher.utils.PublicationProcess.publishInner(PublicationProcess.java:180)
	at org.hl7.fhir.igtools.publisher.utils.PublicationProcess.publish(PublicationProcess.java:61)
	at org.hl7.fhir.igtools.publisher.Publisher.main(Publisher.java:10202)