Can you please paste the request that you are using, you should be able to export it as a curl statement from tools such as postman.
Also post a screenshot of your pipeline where you are calling jsonStreamToDocument (see my example above). Also add a savePipeline to the line following your jsonStreamToDocument. You can then view the resulting pipeline by calling restorePipeline service after from Designer. Also post a screenshot of that too.
As I said it works for me, including both invoke and rad executions.
regards,
John.
#Integration-Server-and-ESB#REST#webMethods