--- a/src/YAMLCommand.h	Sat Dec 05 19:48:52 2020 +0100
+++ b/src/YAMLCommand.h	Wed Dec 23 18:54:41 2020 +0100
@@ -145,7 +145,7 @@
 	string_t consumeScalarEvent() {
 		YAMLEvent_p event = YAMLEvent_p(parser.next());
 		if (event && event->getType() == YAML_SCALAR_EVENT) return fetchScalarValue(event);
-		else throw RelpipeWriterException(L"Invalid YAML structure: expected SCALAR, but got: " + event->getTypeName());
+		else throw RelpipeWriterException(L"Invalid YAML structure: expected SCALAR, but got: " + (event ? event->getTypeName() : L"null event"));
 	}
 
 	bool until(const yaml_event_type_t until, YAMLEvent_p& event) {