You might want to post this question on the PowerExchange forum (not PowerExchange Adapters!) as well. This is one of those cases where a cross-post might indeed help.
The reason is simple: on this forum, the TDM forum, you won't find many people who have a thorough understanding of mainframe technology in general and PWX in particular.
On the PowerExchange forum you won't find many people experienced with TDM, but the mainframe specialists there should be able to help you with this particular error message.