java.lang.NullPointerException
	at org.hl7.fhir.r5.comparison.ProfileComparer.checkAddTypeUnion(ProfileComparer.java:601)
	at org.hl7.fhir.r5.comparison.ProfileComparer.unionTypes(ProfileComparer.java:537)
	at org.hl7.fhir.r5.comparison.ProfileComparer.compareElements(ProfileComparer.java:229)
	at org.hl7.fhir.r5.comparison.ProfileComparer.compareChildren(ProfileComparer.java:330)
	at org.hl7.fhir.r5.comparison.ProfileComparer.compareElements(ProfileComparer.java:246)
	at org.hl7.fhir.r5.comparison.ProfileComparer.compare(ProfileComparer.java:148)
	at org.hl7.fhir.r5.comparison.ComparisonSession.compare(ComparisonSession.java:97)
	at org.hl7.fhir.r5.comparison.ProfileComparer.checkAddTypeUnion(ProfileComparer.java:600)
	at org.hl7.fhir.r5.comparison.ProfileComparer.unionTypes(ProfileComparer.java:537)
	at org.hl7.fhir.r5.comparison.ProfileComparer.compareElements(ProfileComparer.java:229)
	at org.hl7.fhir.r5.comparison.ProfileComparer.compareChildren(ProfileComparer.java:330)
	at org.hl7.fhir.r5.comparison.ProfileComparer.compareElements(ProfileComparer.java:246)
	at org.hl7.fhir.r5.comparison.ProfileComparer.compare(ProfileComparer.java:148)
	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:5078)
	at org.hl7.fhir.igtools.publisher.Publisher.loadConformance(Publisher.java:4947)
	at org.hl7.fhir.igtools.publisher.Publisher.createIg(Publisher.java:1066)
	at org.hl7.fhir.igtools.publisher.Publisher.execute(Publisher.java:896)
	at org.hl7.fhir.igtools.publisher.Publisher.main(Publisher.java:10593)