The case does not advance and we get a broken process. Some how PEGA does not like the DataPage created by a webservice JUST before a change state but when I call the web service DIRECTLY in the activity before a change state, it works i.e. the case advances and there are no broken processes.
Again this DOES NOT happen in 'Current Requestor' context. And hence I thought I will bring it to the notice of the PEGA team. Unfortunately, I cannot provide XML due to my company policies.
I have included the screen shots of how it is being called and you can easily recreate the scenario on your end with the document provided.