I have done 3 steps in BPM
RFC --- BPM --- RFC
RECEIVE step ==> Opens SYNCH ASYNCH bridge and receives RFC request message
SEND synchronous ==> to send RFC request and get the RFC response.
SEND ==> Closes SYNCH ASYNCH bridge and Send's response back to the RFC.
In my last send step (response back) I am getting message
"Message pipeline PE_ADAPTER unknown XML message not found" .