PO status "ERROR in PROCESS" after confirmation

Hello Experts,

problem is :

When i create Purchase order its successfuly gets replicated in the Backend as we are on ECS scenario.Now when i create Confirmation the confirmation is also successfully created in the backend system but PO status gets changed to "ERROR in PROCESS" . i check in RZ20 and error is : "Purchase order 2400002371: Transfer Failed; Resubmit" means Application error while updating purchase orders in the back-end system.

I check my port settings and message type in partner profiles looks OK to me otherwise Confir mation will not cretae in the backend system but yes i can see its created and all my data is fine then why for all the Purchase order after creating confirmation status gets Change ?

Thanks in advance

Smriti