To reset a data tag that has a refType attribute pointing to a type, you must ensure that the type already exists in the list of types maintained by the type externalizer. This is because the data externalizer will ask the types externalizer to create an instance of a data element of that type. Therefore, if the refType attribute points to a type that is not listed, you must reset the types externalizer to add the referenced type before you can reset the data tag that contains the refType attribute. In summary, the correct order in which to reset types and typed data is: