I dont have this client but probably they implemented a new line in the Build-XML to confuse the extractor. Apparently most extractors can't handle missing files in the EPK and crash. Nevertheless I know there are extractors whitch can handle those poor encryptions (try out

one).
As I said I don't have the rr Client so I did not test any extractors.
It's possible that they used other encryption techniques or they found other ways to make sure the decryption fails/crashes.