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.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:250)
	at org.hl7.fhir.igtools.publisher.Publisher.checkConformanceResources(Publisher.java:3926)
	at org.hl7.fhir.igtools.publisher.Publisher.loadConformance(Publisher.java:3832)
	at org.hl7.fhir.igtools.publisher.Publisher.createIg(Publisher.java:877)
	at org.hl7.fhir.igtools.publisher.Publisher.execute(Publisher.java:732)
	at org.hl7.fhir.igtools.publisher.Publisher.main(Publisher.java:8414)
	at org.hl7.fhir.igtools.publisher.utils.PublicationProcess.runBuild(PublicationProcess.java:333)
	at org.hl7.fhir.igtools.publisher.utils.PublicationProcess.doPublish(PublicationProcess.java:232)
	at org.hl7.fhir.igtools.publisher.utils.PublicationProcess.publishInner(PublicationProcess.java:181)
	at org.hl7.fhir.igtools.publisher.utils.PublicationProcess.publish(PublicationProcess.java:59)
	at org.hl7.fhir.igtools.publisher.Publisher.main(Publisher.java:8211)