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:548)
	at org.hl7.fhir.r5.comparison.ProfileComparer.unionTypes(ProfileComparer.java:488)
	at org.hl7.fhir.r5.comparison.ProfileComparer.compareElements(ProfileComparer.java:207)
	at org.hl7.fhir.r5.comparison.ProfileComparer.compareChildren(ProfileComparer.java:307)
	at org.hl7.fhir.r5.comparison.ProfileComparer.compareElements(ProfileComparer.java:224)
	at org.hl7.fhir.r5.comparison.ProfileComparer.compare(ProfileComparer.java:131)
	at org.hl7.fhir.r5.comparison.ComparisonSession.compare(ComparisonSession.java:92)
	at org.hl7.fhir.igtools.publisher.PreviousVersionComparator.finishChecks(PreviousVersionComparator.java:252)
	at org.hl7.fhir.igtools.publisher.Publisher.checkConformanceResources(Publisher.java:4012)
	at org.hl7.fhir.igtools.publisher.Publisher.loadConformance(Publisher.java:3918)
	at org.hl7.fhir.igtools.publisher.Publisher.createIg(Publisher.java:893)
	at org.hl7.fhir.igtools.publisher.Publisher.execute(Publisher.java:748)
	at org.hl7.fhir.igtools.publisher.Publisher.main(Publisher.java:8566)
	at org.hl7.fhir.igtools.publisher.utils.PublicationProcess.runBuild(PublicationProcess.java:342)
	at org.hl7.fhir.igtools.publisher.utils.PublicationProcess.doPublish(PublicationProcess.java:241)
	at org.hl7.fhir.igtools.publisher.utils.PublicationProcess.publishInner(PublicationProcess.java:190)
	at org.hl7.fhir.igtools.publisher.utils.PublicationProcess.publish(PublicationProcess.java:60)
	at org.hl7.fhir.igtools.publisher.Publisher.main(Publisher.java:8363)