BPMN21 — XML Schema not valid

The official XML Schema for BPMN 2.0 (http://www.omg.org/spec/BPMN/20100501/BPMN20.xsd) is not valid.

• It imports a schema with the schemaLocation "http://www.omg.org/spec/BPMN/20100501/Diagram Interchange.xsd", which does not exist.
  Even when using the correct schemaLocation of "http://www.omg.org/spec/BPMN/20100501/DI.xsd", the namespace does not match (http://www.omg.com/di/1.0.0 vs. http://www.omg.org/spec/DD/20100524/DI)
  (Note that one uses "omg.com" and the other uses "omg.org".)

• It includes the Schema "http://www.omg.org/spec/BPMN/20100501/Semantic.xsd", but its targetNamespace http://www.omg.org/spec/BPMN/20100524/MODEL does not match the including schema's value.

• The website http://www.omg.org/spec/BPMN/2.0/ has missmatching links for several items:
  • "http://www.omg.org/spec/BPMN/20100501/DI.xsd" links to "http://www.omg.org/spec/BPMN/20100501/BPMNDI.xsd"
  • "http://www.omg.org/spec/BPMN/20100501/Semantic.xsd" links to " http://www.omg.org/spec/BPMN/20100501/BPMNDI.xsd"